Entity - Detached Duplex, Bungalow and Apartment Block

Superstructure - Floor

In building construction, the superstructure refers to the part of a building that is above ground level, encompassing elements such as walls, floors, roofs, columns, and beams. Within this context, the floor is a critical component that serves as a platform for supporting loads and facilitating movement. Floors contribute significantly to the functionality, aesthetics, and structural stability of a building.

1.1. In-Situ Concrete Works

In building construction, in-situ concrete works for the superstructure roof involve the on-site casting of concrete to form the roof slab and related structural components. This includes the construction of beams, slabs, and supporting columns directly at the site, ensuring a seamless, integrated structure. The process often involves formwork, reinforcement installation, and concrete pouring, followed by curing to achieve the desired strength. It ensures the roof is solid, durable, and tailored to the building's specific requirements.

1.1.1. Reinforcement Bars in Columns / Beams / Slab

In building construction, placing reinforcement steel bars for columns and beams is crucial. Following structural designs, workers position steel rods vertically within column formwork, ensuring proper spacing and alignment. The bars, typically arranged in a cage-like configuration, are secured with wire ties or supports to maintain their position. Attention to detail is paramount to achieve structural integrity, ensuring the bars are free from debris and properly aligned according to engineering specifications. This meticulous process ensures the column can withstand the loads it will bear, enhancing the overall strength and stability of the building's superstructure.

Assumptions:

The task is to Install reinforcement steel bars in column and beams. The materials used are reinforcement steel bars and binding wires. The standard length of reinforcement steel bars is 12 metres. The steel bars have the different diameters ranging from 32mm to 8mm. The standard size of binding wire is 20kg per roll.

Calculations:

For Different sizes of reinforcement steel bars:

A. 32mm Steel bar:

Weight per metre: 6.318 kg
Weight per 12m bar: 6.318 kg/m x 12m = 75.816 kg
Number of bars per tonne: 1 tonne / 75.816 kg ≈ 13 bars

B. 25mm Steel Bar:

Weight per metre: 3.856 kg
Weight per 12m bar: 3.856 kg/m x 12m = 46.272 kg
Number of bars per tonne: 1 tonne / 46.272 kg ≈ 22 bars

C. 20mm Steel bar:

Weight per metre: 2.468 kg
Weight per 12m bar: 2.468 kg/m x 12m = 29.616 kg
Number of bars per tonne: 1 tonne / 29.616 kg ≈ 34 bars

D. 16mm Steel bar:

Weight per metre: 1.58 kg
Weight per 12m bar: 1.58 kg/m x 12m = 18.96 kg
Number of bars per tonnes: 1 tonne / 18.96 kg ≈ 53 bars

E. 12mm Steel Bar:

Weight per metre: 0.888 kg
Weight per 12m bar: 0.888 kg/m x 12m = 10.656 kg
Number of bars per ton: 1 tonnes / 10.656 kg ≈ 94 bars

F. 10mm Steel bar:

Weight per metre: 0.617 kg
Weight per 12m bar: 0.617 kg/m x 12m = 7.404 kg
Number of bars per ton: 1 tonnes / 7.404 kg ≈ 135 bars

G. 8mm Steel bar:

Weight per metre: 0.395 kg
Weight per 12m bar: 0.395 kg/m x 12m = 4.74 kg
Number of bars per ton: 1 tonnes / 4.74 kg ≈ 211 bars

2. Binding wire:

Weight per roll: 20 kg
Quantity required per ton of steel bars: 12 kg
Number of rolls required per tonne: 12 kg / 20 kg per roll = 0.6 rolls
Cost of binding wire per tonne of reinforcement bars: 42,000 x 0.6 = 25,200

Daily equipment rentals calculations:

Cutting machine: 50,000.00/day
Angle grinder: 25,000.00/day
Rebar bender (Electric): 150,000.00/day
Total equipment Cost: 225,000.00/day
Average productivity: 1 tonne/day
Equipment cost per tonne: 225,000.00

Service:

Iron bender skilled: 10,000.00/day
Iron bender semi-skilled Placer: 7,500/day
Iron bender semi-skilled: 7,500/day
Total service cost: 25,000.00/day
Average productivity: 1 tonne/day
Service cost per tonne: 25,000.00

Total Installation cost per tonne:

This includes materials, equipment, and service costs. The exact cost depends on the size of the steel bars used. For example, if using 20mm steel bars:
Material Cost: Cost of steel bars ₦1,200,000.00 + (10% waste ₦120,000.00) + binding wire cost)
= (₦1,200,000.00+120,000.00+ ₦25,200)
= 1,345,200.00.
Total Cost per tonne = Material Cost + 225,000.00 (equipment) + 25,000.00 (service)
= ₦1,345,200.00 + ₦225,000.00 + ₦25,000.00
=₦1,595,200.00/tonne.

Schedule for Reinforcement Bars:

Assumed quantities: 1 tonne
Total material cost per tonne: ₦1,345,200.00
Equipment cost per tonne: ₦225,000.00
Service cost per tonne: ₦25,000.00
Built up rate per tonne: ₦1,595,200.00/tonne

1.1.2. Fix Formwork to Columns

Installing formwork for concrete columns involves several key steps. First, measure and mark the column positions on the foundation or slab. Next, assemble the formwork panels, ensuring they are clean and properly aligned. Securely brace the formwork to maintain its shape and prevent movement during concrete pouring. Install spacers to ensure the correct concrete cover for reinforcement. Check all dimensions and plumb the formwork to guarantee verticality. Apply form release agent to facilitate removal later. After ensuring all reinforcements and embedded items are in place, the formwork is ready for concrete pouring.

Assumptions:

The task involves fixing formwork to sides of columns. The proposed area to be covered by formwork is 30 square metres (m²)
The formwork to be used Marine board and Hardwood:
Marine board size: 1.2 x 2.4 metres (2.88 m²), Hardwood size 50 x 100 x 3.6 metres
Cost per piece of marine boards: ₦11,000.00
Cost per piece of Hardwood: ₦650.00
Circular saw is the equipment used.

Calculations:

A. Marine board: the area of the size is (2.88 m²), to cover 30 metres square, 30 / 2.88 = 10.41, rounded up to 11 boards. The total cost for marine boards is 11 x ₦11,000.00 = ₦121,000.00.

B. Hardwood: from site data, 4 pieces of 50 x 100 x 3.60m hardwood is used per marine board averagely, the total pieces needed is 11 boards x4 pieces = 44 pieces. The total cost for 50 x 100 hardwood: 44 x ₦650.00 = ₦28,600.00.

C. Nails: 0.9 kg of wire nails is used to nail per marine board as the constant, the total nails needed is 1 boards x 0.9 kg = 9.9 kg, rounded to 10 kg. The total cost for nails: 10 x ₦1,600.00 = ₦16,000.00.

Total material cost:

The total cost for the use of marine board as formwork is ₦121,000.00 (boards) + ₦28,600.00 (hardwood) + ₦16,000.00 (nails)
= ₦165,600.00.
The material cost per square metre: ₦165,600 / 30 m² = ₦5,520.00/m²
Assuming the formwork can be reused thrice: ₦5,520 / 3 = ₦1,840.00/m².

For the service required:

A skilled Carpenter will charge ₦6,000 per day, while a semi-skilled carpenter is paid ₦3,000 per day. The total cost of labour is ₦9,000 per day. The labour output is 15 square metres per day, per square metre is ₦9,000 / 15 m² = ₦600.00/m².

Equipment used:

For the circular saw rental: The daily rental cost: ₦12,000.00. The daily production capacity is 15 m². The equipment cost per cubic metre is ₦12,000 / 15 m² = ₦800.00/m²

Total Cost:

The total cost for per square metre of fixing formwork to sides of concrete base, it includes the cost of materials, labour, and equipment. Total cost is the addition of the cost per square metre of material costs of ₦1,840.00/m², service cost of ₦600.00/m² and equipment cost ₦800.00/m²which gives ₦3,240.00/m².

Schedule for Fixing Formwork in Columns:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦5,520.00/m²
Material cost for three use case: ₦1,840.00/m²
Service or labour cost per square metre: ₦600.00/m²
Equipment cost per square metre: ₦800.00/m²
Built up rate per square metre: ₦3,240.00/m²

1.1.3. Fix Formwork in Slabs and Beams

The installation of formwork for a concrete slab in building superstructure involves several steps. First, accurate measurements and layout are marked on the site. Shuttering panels and supports (props and scaffolding) are then assembled to create a mold that matches the slab's dimensions. The formwork must be sturdy and level to support the weight of the concrete and ensure a smooth finish. Once assembled, the formwork is secured and aligned, with all joints sealed to prevent leakage.

Assumptions:

The tasks involves fixing formwork to soffits of slab and beams. The proposed area to be covered by formwork is 120 square metres (m²). The length is 12 metres and breadth is 10 metres.
Sheathing is the platform that will receive the concrete work. It can steel, wooden plank or marine board
Stringer and Joist connect the sheathing with the shoring. It could be H-beams formwork or 2" x 3" (50x75mm) hardwood spaced at 600mm for wooden formwork.
Shoring is the vertical member that transfers the dead load of the concrete to another floor. It could be Steel pipes for steel formwork or bamboo spaced at 600mm for wooden formwork
The sheathing formwork to be used is Marine board and Hardwood, while the shoring material to be used is Bamboo.
Marine board size: 1.2 x 2.4 metres (2.88 m²), Hardwood size 50 x 75 x 3.6 metres
Cost per piece of marine boards: ₦11,000.00
Cost per piece of Hardwood: ₦650.00
The average length of a Bamboo is 6m. The assumed headroom height is 3m.
Circular saw is the equipment used.

Calculations:

The calculation for the Stringers is as follows, the longer length is 12m, to determine the number of lines; 10m / 0.6m + 1 = 18 lines. The total length of Stringers will be 12m x 18 = 216m. The number of hardwood will be 216m / 3.6m = 60 pieces.
The calculation for the Joist is as follows, the shorter length is 10m, to determine the number of lines will be 12m / 0.6m + 1 = 21 lines. The total length of Joist will be 10m x 21 = 210m. The number of hardwood pieces will be 210 / 3.6m = 58 pieces
The calculation for the shoring is as follows, the number of points where there will be Bamboo will be 18 lines x 21 lines = 378 points. The average length of a Bamboo is 6m. The assumed headroom height is 3m. The total length of shoring is 1137 metres. The number of bamboo required: 1137m / 6m = 189 pieces, which is approximated to 200 pieces for a load of Bamboo.

The cost calculations:

A. Marine board: the area of the size is (2.88 m²), to cover 120 metres square, 120 / 2.88 = 41.66, rounded up to 42 boards. The total cost for marine boards is 11 x ₦11,000.00 = ₦420,000.00.

B. Hardwood: 60 pieces of stringers and 58 pieces of joist would be used, 118 pieces of 50 x 75 x 3.60m hardwood is used, the total cost for 50 x 75 hardwood will be 118 x ₦450.00 = ₦53,100.00.

C. Nails: 0.25 kg of wire nails is used to nail per square metre as the constant, the total nails needed is 120 x 0.25 kg = 30 kg. The total cost for nails: 30 x ₦1,600.00 = ₦48,000.00.

D. Bamboo: A load of Bamboo costs ₦100,000.

Total material cost:

The total cost for the use of marine board as formwork is ₦420,000.00 (boards) + ₦53,100.00 (hardwood) + ₦48,000.00 (nails)
= ₦521,100.00.
The material cost per square metre: ₦521,100 / 120 m² = ₦4,342.50/m²
Assuming the formwork can be reused twice: ₦4,342.5 / 2 = ₦2,175.25/m²

For the service required:

A skilled Carpenter will charge ₦6,000 per day, while a semi-skilled carpenter is paid ₦3,000 per day. The total cost of labour is ₦9,000 per day. The labour output is 15 square metres per day, per square metre is ₦9,000 / 8 m² = ₦1,125.00/m²

Equipment used:

For the circular saw rental: The daily rental cost: ₦12,000.00. The daily production capacity is 15 m². The equipment cost per cubic metre is ₦12,000 / 8 m² = ₦1,500.00/m²

Total Cost:

The total cost for per square metre of fixing formwork to sides of concrete base, it includes the cost of materials, labour, and equipment. Total cost is the sum of the cost per square metre of material costs of ₦2,175.25/m², service cost of ₦1,125.00/m² and equipment cost ₦1,500.00/m² which gives a total of ₦4,800.25/m².

Schedule for Fixing Formwork in Slabs and Beams:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦2,175.25/m²
Material cost for two use case: ₦1,840.00/m²
Service or labour cost per square metre: ₦1,125.00/m²
Equipment cost per square metre: ₦1,500.00/m²
Built up rate per square metre: ₦4,800.25/m²

1.1.4. Pour Concrete to Columns / Beams / Slabs

Pouring concrete in column bases during the foundation stage of building construction involves filling excavated areas with concrete to support vertical load-bearing columns. This process ensures a strong connection between the building's structure and its foundation, providing stability and load distribution. Once poured, the concrete is allowed to cure, forming a solid and durable foundation for the building's superstructure. This step is critical for ensuring the structural integrity and longevity of the entire construction project.

Assumptions:

Concrete Mix Composition:

The task involves pouring of concrete in 1 cubic metre of concrete in column base, column starter and concrete slab.
Ratio: Cement to Sand to Granite is 1:2:4.
Total Portions: The mix consists of 7 parts.
Void in Aggregates: There is a 54% void in the aggregates to account for material shrinkage and waste.
Mix Volumes: To prepare 1 cubic metre of wet concrete, 1.54 cubic metres of dry concrete is needed.
Water Cement Ratio: The water-cement ratio is 0.5.
The output of the Workers is 2 cubic metres daily.
The daily rental cost of a concrete mixer is ₦120,000.00.

Calculations:

Materials required:

A. Cement: The volume of cement required is 1.54 cubic metres x (1/7) = 0.22 cubic metres. The cement density is 1440 kg/m³. To get the mass of Cement, we will multiply the volume by the density. The density of Sand is 1600 kg/m³.The mass of cement will be 0.22 cubic metres x 1440 kg/m³ = 316.8 kg. The number of bags of cement is (50 kg each): 316.8 kg / 50 kg =2.77 bags ≈ 7 bags.

B. Sand: The volume of sand required is 1.54 cubic metres x (2/7) = 0.44 cubic metres. The density of Sand is 1600 kg/m³. To get the mass of Sand, we will multiply the volume by the density. The density of Sand is 1600 kg/m³.The mass of sand will be 0.44 cubic metres x 1600 kg/m³ = 704 kg. The weight of Sand in tonnes is 704 kg / 1000 =0. 704 Tonne

C. Granite: The volume of granite required is 1.54 cubic metres x (4/7) = 0.88 cubic metres. To get the mass of Cement, we will multiply the volume by the density. The density of Sand is 1600 kg/m³.The density of granite is 1700 kg/m³. The mass of granite will be 0.88 cubic metres x 1700 kg/m³ = 1496 kg. The weight of granite in tonnes is 1472 kg / 1000 = 1.496 Tonnes

D. Water: The water cement ratio for concrete is 0.5. The volume required is 0.22 cubic metres x 0.5 = 0.11 cubic metres. When converted to litres, 0.11 cubic metres x 1000 = 110 litres

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 2 cubic metres per day): ₦8,500 / 2 = ₦4,250 per cubic metre.

Equipment Used:

For the concrete mixer rental: The daily rental cost: ₦120,000.00. The daily production capacity is 2 cubic metres. The equipment cost per cubic metre: ₦120,000 / 2 = ₦60,000 per cubic metres

Summary:

Materials per cubic metre:

Cement: 7 bags = 7 x 7,700 per bag =₦53,900.00
Sand: 0.704 tonnes = 0.704 x 8,000= ₦5,632.00
Granite: 1.496 tonnes= 1.496 x 13,000.00=₦19,448.00
Water: 110 litres
Total cost of materials =₦78,980.00

The total cost per cubic metre of concrete:

The total cost for pouring 1 cubic metre of concrete includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦78,980.00 (Material costs), ₦4,250.00 (Service cost) and ₦60,000.00(Equipment cost) which gives a total of ₦143,230.00.

Schedule For Pouring Concrete in Columns / Beams / Slabs:

Assumed quantities: 1 cubic metre
Total material cost per cubic metre: ₦78,980.00
Service or labour cost per cubic metre: ₦4,250.00
Equipment cost per cubic metre: ₦60,000.00
Built up rate per cubic metre: ₦143,230.00

1.2. Masonry

Masonry in building construction processes involves using materials like bricks, stones, and concrete blocks to create load-bearing and non-load-bearing walls, chimneys, fireplaces, and facades, and other structural elements above the foundation. It encompasses laying units in specific patterns with mortar to ensure stability, strength, and aesthetic appeal. Masonry work requires precision to maintain structural integrity, proper alignment, and adherence to building codes. It also involves installing reinforcement, controlling moisture, and providing insulation to enhance the durability and functionality of the superstructure.

1.2.1. Lay 225 x 450mm Sandcrete Block Wall

Sandcrete blocks are meticulously stacked on the mortar, then filled with concrete to increase its strength. Each block is checked for level and plumb, with a thin mortar layer spread before placing the next course. Staggering the block joints, row by row, builds a strong, interlocking foundation wall. This precise process continues until the entire foundation reaches its planned height.

Assumptions:

The task involves laying of sandcrete blocks for 1 square metre of block wall.
Mortar mix ratio: Cement to Sand is 1:6, 1 part cement to 6 parts sand, the mix consists of 7 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5.
Size of block in consideration is 450mmx 225mm x 225mm blocks.

Calculations:

Materials for mortar composition:

A. Cement: The cement to sand ratio 1:6 (1 part cement to 6 parts sand). The volume of cement will (1/7) x 1.20m³ of wet concrete. This gives the volume of 0.17 m³. Using the density 1440 kg/m³, the weight of cement will 0.17 m³ x 1440 kg/m³ = 246.86 kg.

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg =4.93 bags ≈ 5 bags.

B. Sand: The cement to sand ratio 1:6 (1 part cement to 6 parts sand).The volume of sand required is (6/7) x 1.20 cubic metres = 1.03 m³. The density of Sand is 1600 kg/m³. The weight of sand will be 1.03m³ x 1600 kg/m³ = 1645.71 kg. The weight of Sand in tonnes is 1645.71 kg / 1000 =1.645 tonnes.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.17 cubic metres x 0.5 = 0.085 cubic metres. When converted to litres, 0.85 cubic metres x 1000 = 85.71 litres.

D. Blocks: The size of the block in consideration is 450mmx 225mm x 225mm blocks. The volume of mortar needed at one end of the one block is gotten by 0.450m x 0.225m x 0.225m = 0.02278125 m³ (V1). The Block is added to 25mm thick mortar which give 0.475m x 0.25 x .25 which gives a volume of 0.02268125m³ (V1).

The mortar is then added to the blocks with the dimensions 0.45 x 0.225 x 0.25 which give a volume of 0.02671875 m³ (V2). There is a void in the two sides in the block that is to be deducted is 2 x 0.15m x .15m x 0.025m=0.001125m³ (D1). The volume of mortar per block is mortar volume per block is the difference between V2 and (V1+D1) = 0.02278125 m³ - (0.02671875m³+ 0.001125m³) = 0.0028125m³/Block. There are 10 blocks in a square metre of block wall and the volume of mortar per square metre for 225 Blockworks is 0.028125 m³/m².

For the materials in the mortar per square metre:

10 blocks of 225mm thickness are required per square metre.
The Cement for mortar, in 1 m³ of mortar, 4.937142857 bags of 50 kg each are required. For 0.028125 m³/m², the amount of cement 0.028125 m³ x 4.937142857 =0.13948 bags/m².
The required Sand for mortar, In 1 m³ of mortar, 1.64571 tonnes of sand are required. For 0.028125 m³/m², the amount of sand 0.028125 m³ x 1.64571 = 0.04631 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.028125 m³ of mortar: Amount of water 0.028125 m³ x 85.71litres = 2.4098 litres.

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 5.5 m² per day): ₦8,500 / 5.5 m² = ₦1,545.45 per square metre.

Total cost of materials used per square metre:

Blocks- 10 blocks make 1 square metre = 10 x 750= ₦7,500.00
Cement- 0.13948 bags x 7,700.00= ₦1,073.99
Sand- 0.04631 x tonnes x 8,000.00 = ₦370.48
Total cost of materials=₦8,944.47

Total cost:

The cost of laying sandcrete block wall per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦8,944.47 (Material costs) and ₦1,545.00 (Service cost) which gives a total of ₦10,489.92.

Schedule for Laying of 225 x 450mm Sandcrete Block Wall:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦8,944.47
Service or labour cost per square metre: ₦1,545.00
Built up rate per square metre: ₦10,489.92

1.2.2. Lay 150 x 450mm Sandcrete block wall in Superstructure

Assumptions:

The task involves laying of sandcrete blocks for 1 square metre of blockwall.
Mortar mix ratio: Cement to Sand is 1:6, 1 part cement to 6 parts sand, the mix consists of 7 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5.
Size of block in consideration is 450mmx 150 mm x 225mm blocks

Calculations:

Materials for mortar composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg =4.93 bags ≈ 5 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.17 cubic metres x 0.5 = 0.085 cubic metres. When converted to litres, 0.85 cubic metres x 1000 = 85.71 litres.

D. Blocks: The size of the block in consideration is 450mmx 150mm x 225mm blocks. The volume of mortar needed at one end of the one block is gotten by 0.450m x 0.150mm x 0.225m = 0.0152 m³ (V1). The Block is added to 25mm thick mortar which give 0.475m x 0.15 x .25 which gives a volume of 0.0178m³ (V2).

The mortar is then added to the blocks with the dimensions 0.45 x 0.15 x 0.25 which give a volume of 0.0152 m³ (V2). There is a void in the two sides in the block that is to be deducted is 2 x 0.15m x .08m x 0.025m=0.006m³ (D1). The volume of mortar per block is mortar volume per block is the difference between V2 and (V1+D1) = 0.02278125 m³ - (0.02671875m³+ 0.001125m³) = 0.0028125m³/Block. There are 10 blocks in a square metre of block wall and the volume of mortar per square metre for 225 Blockworks is 0.028125 m³/m².

For the materials in the mortar per square metre:

10 blocks of 225mm block wall are required per square metre.
The Cement for mortar, In 1 m³ of mortar, 4.937142857 bags of 50 kg each are required. For 0.028125 m³/m², the amount of cement 0.028125 m³ x 4.937142857 =0.13948 bags/m².
The required Sand for mortar, in 1 m³ of mortar, 1.64571 tonnes of sand are required. For 0.028125 m³/m², the amount of sand 0.028125 m³ x 1.64571 = 0.04631 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.028125 m³ of mortar: Amount of water 0.028125 m³ x 85.71litres = 2.4098 litres.

For the service required:

A skilled mason will charge ₦5,000.00 per day, while a semi-skilled mason is paid ₦3,500.00 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 5.5 m² per day): ₦8,500.00 / 5.5 m² = ₦1,545.45 per square metre.

Total cost of materials used per square metre:

Blocks- 10 blocks makes 1 square metre = 10 x 650.00= ₦6,500.00
Cement- 0.13948 bags x 7,700.00= ₦1,073.99
Sand- 0.04631 x tonnes x 8,000.00 = ₦370.48
Total cost of materials=₦8,944.47

Total cost:

The cost of laying sandcrete block wall per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦8,944.47 (Material costs) and ₦1,545.00 (Service cost) which gives a total of ₦10,489.92

Schedule for Laying of 150 x 450mm Sandcrete Block Wall:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦8,944.47
Service or labour cost per square metre: ₦1,545.00
Built up rate per square metre: ₦10,489.92

1.3. Doors and Windows

1.3.1. Install Doors

During the superstructure phase of building construction, door installation involves several steps. First, precise measurements are taken to ensure the door fits the frame accurately. Next, hinges and hardware are affixed to the door, allowing it to swing smoothly. Then, the frame is prepared, ensuring its level and securely anchored. Finally, the door is carefully placed into the frame, adjusted as needed, and secured in place. Attention to detail and adherence to building codes are crucial to ensure the door functions properly and contributes to the structural integrity of the building.

Assumptions:

The task involves installing a 2.1m x 0.9m panel metal door.
The door is installed by a Carpenter.
The labour output is 3 doors per day.

Calculations:

The cost of the 2.1m x 0.9m metal panel doors is ₦200,000.00.

For the service required:

A skilled Carpenter will charge ₦6,000 per day, while a semi-skilled carpenter is paid ₦3,000 per day. The total cost of labour is ₦9,000 per day. The labour output is 3 doors per day, per door is ₦9,000 / 3 doors = ₦3000.00/door.

Total cost

The total cost installing a metal panel door. Total Cost is the addition of ₦200,000.00 (Material costs) and ₦3,000.00 (Service cost) which gives a total of ₦203,000.00 per door.

Schedule for Installation of a 1-Panel Metal Door

Assumed quantities: 1 door
Total material cost per door: ₦200,000.00.
Service or labour cost per door: ₦3,000.00
Built up rate per door: ₦203,000.00

1.3.2. Install Windows

In building construction, the installation of windows within the superstructure involves several steps. First, the openings for the windows are prepared, ensuring they align with the architectural plans. Next, the window frames are securely positioned and anchored into place. Then, weatherproofing measures such as flashing and caulking are applied to prevent water infiltration. Finally, the windows themselves are installed within the frames, carefully sealed to ensure energy efficiency and structural integrity. This process requires precision and attention to detail to create a durable and functional building envelope.

Assumptions:

The task involves installing a fabricated 1.2m x 1.2m casement window.
The window is installed by a skilled mason and semi-skilled Mason.
The output per day is 5 windows.

Calculations:

The cost of the 1.2m x 1.2m casement window is ₦120,000.00.

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500.00 per day. The total cost of labour is ₦8,500.00 per day. The labour cost per window ₦8,500.00 / 5 windows = ₦1,700.00 per window

Total cost

The total cost installing a window. Total Cost is the addition of ₦120,000.00 (Material costs) and ₦1,700.00 (Service cost) which gives a total of ₦121,700.00 per window.

Schedule for Installation of a 1.2m x 1.2m Casement Window:

Assumed quantities: 1 casement window.
Total material cost per window: ₦120,000.00.
Service or labour cost per window: ₦1,700.00.
Built up rate per window: ₦121,700.00.

1.4. Metal Work

Metal work in the superstructure-floor process involves the installation of steel beams, columns, and reinforcement bars to support the building's structure. This includes fabricating and assembling metal components for floors, providing strength and stability. Metalwork also ensures proper load distribution, helping floors withstand weight and stress. It may include staircases, railings, and other metal fixtures, all essential for the building’s structural integrity and longevity, forming the backbone of the superstructure.

1.4.1. Install Burglary Proof

In building construction, integrating burglary-proof measures into the superstructure involves meticulous planning and execution. Initially, structural engineers assess the building's layout to determine vulnerable entry points. Then, specialized contractors install reinforced doors, windows, and security grilles, utilizing robust materials like steel or aluminum. Incorporating these measures seamlessly into the superstructure ensures structural integrity while fortifying against unauthorized access. Finally, rigorous testing verifies the effectiveness of the burglary-proof installations, guaranteeing they meet safety standards and provide reliable protection against potential threats.

Assumptions:

The task involves installing a fabricated 1.2m x 1.2m steel burglary proof.
The door is installed by a skilled mason and semi-skilled mason.
The output per day is 5 steel burglary proofs.

Calculations:

The cost of the 1.2m x 1.2m steel burglary proof is ₦60,000.00.

For the service required:

A skilled mason will charge ₦5,000.00 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500.00 per day. The labour cost per steel burglary proof ₦8,500.00 / 5 steel burglary proof. = ₦1,700.00 per window

Total cost:

The total cost installing a steel burglary proof. The total Cost is the addition of ₦60,000.00 (Material costs) and ₦1,700.00 (Service cost) which gives a total of ₦61,700.00 per steel burglary proof.

Schedule for Installing Burglary Proof:

Assumed quantities: 1 burglar proof.
Total material cost per burglary proof: ₦60,000.00.
Service or labour cost per door: ₦1,700.00
Built up rate per door: ₦61,700.00

1.5. Floor, Wall, Ceiling and Roof Finishings

In building construction, the superstructure processes for floor, wall, ceiling, and roof finishes involve the installation of various materials and finishes that contribute to the building's aesthetics, functionality, and durability. Floor finishes may include tiles, hardwood, or carpet. Wall finishes can involve plaster, paint, or cladding. Ceiling finishes often consist of drywall, plaster, or tiles.

1.5.1. Cement Sand Screeded Bed for Floor Finish

The subfloor is prepped, ensuring levelness. A cement-sand mix is then poured and meticulously smoothed with a long straightedge to create a perfectly flat screed. This provides a stable and even base for the final floor finish. The thickness of the screed depends on the floor covering (tiles require a thinner layer than carpet) and any underfloor features like radiant heating. Once cured, the screed is ready for the chosen floor finish to be installed, transforming the raw space into a beautiful and functional floor.

Assumptions:

The tasks involves pouring of cement sand screeded bed for floor finish
Mortar mix ratio: Cement to Sand is 1:3, 1 part cement to 4 parts sand, the mix consists of 4 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5
The bedding thickness of 36 mm

Calculations:

Materials for screeded bed composition:

A. Cement: The cement to sand ratio 1:3 (1 part cement to 4 parts sand). The volume of cement will (1/4) x 1.20m³ of wet concrete. This gives the volume of 0.30 m³. Using the density 1440 kg/m³, the weight of cement will 0.30 m³ x 1440 kg/m³ = 432 kg

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg = 8.64 bags ≈ 9 bags.

B. Sand: The cement to sand ratio 1:4 (1 part cement to 4 parts sand). The volume of sand required is (3/4) x 1.20 cubic metres = 0.90 m³. The density of Sand is 1600 kg/m³. The weight of sand will be 0.90m³ x 1600 kg/m³ = 1440 kg. The weight of Sand in tonnes is 1645.71 kg / 1000 =1.440 tonnes.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.3 cubic metres x 0.5 = 0.15 cubic metres. When converted to litres, 0.15 cubic metres x 1000 = 150 litres.

For the materials in the mortar per square metre:

The average bedding thickness for a bedding thickness of 36 mm (or 0.036 metres), the volume required per square metre is 0.036 m³/m².
The Cement for mortar, In 1 m³ of mortar, 9 bags of 50 kg each are required. For 0.036 m³/m², the amount of cement 0.036 m³/m² x 9 bags = 0.324 bags/m²
The required Sand for mortar, In 1 m³ of mortar, 1.440 tonnes of sand are required. For 0.036 m³/m², the amount of sand 0.036 m³ x 1.440 = 0.05184 tonnes
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.036 m³ of mortar: Amount of water 0.036 m³ x 85.71litres = 2.4098 litres.

Total cost of materials used per square metre:

Cement- 0.324 bags x 7,700.00= ₦2,494.00
Sand- 0.05184 tonnes x 8,000.00 = ₦414.72
Total cost of materials = ₦2,908.72

For the service required:

A skilled mason will charge ₦5,000.00 per day, while a semi-skilled mason is paid ₦3,500.00 per day. The total cost of labour is ₦8,500.00 per day. The labour cost per cubic metre (assuming 25 m² per day): ₦8,500 / 25 m² = ₦340.00 per square metre.

Total cost of materials used per square metre

Cement- 0.324 bags x 7,700.00= ₦2,494.00
Sand- 0.05184 tonnes x 8,000.00 = ₦414.72
Total cost of materials = ₦2,908.72

Total cost

The cost of laying cement sand screeded bed for floor finish per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦2,908.72 (Material costs) and ₦340.00 (Service cost) which gives a total of ₦3,248.72

Schedule for Cement Sand Screeded Bed for Floor Finish:

Assumed quantities: 1 square metre
Total material square metre: ₦60,000.00.
Service or labour square metre: ₦1,700.00
Built up rate square metre: ₦61,700.00

1.5.2 fix floor tile on screeded floor finish

The screeded floor, dry and level, becomes the stage for the tile. A special adhesive, chosen for the tile type and screed material, is spread with a notched trowel. Each tile is carefully placed, pressed firmly, and adjusted for a level surface. Tile spacers ensure consistent gaps for grouting. Once the adhesive sets, grout, a cement-based mixture, fills the gaps, creating a watertight and finished surface. The final touch? Removing excess grout and polishing the tiles for a beautiful, functional floor.

Assumptions:

The task involves fixing floor tile on screeded floor finish
The tile size is 0.6 mx 0.6m, with 3 pieces per pack.
There is a 5% wastage on the tile used purchase
Water cement ratio: The water-cement ratio is 0.5
The bedding thickness of 36 mm

Calculations:

Materials used for floor tiles:

A. Tiles: The floor tiles used are the 0.6 metres long and 0.6 metres wide, each tile covers an area of 0.36 square metres. The package of tile contains 3 tiles. The total area covered by one package is 3 tiles x 0.36 square metres per tile = 1.08 square metres. To account for waste, let's add 5% to the total area covered by one package. 5% of 1.08 square metres is 0.054 square metres. The total area covered by one package, including waste, is 1.08 + 0.054 = 1.134 square metres. If we want to know how many packages we need for 1 square metre of area, we divide 1 by the area covered by one package (1.134 square metres). This gives us approximately 0.88 packages per square metre.

B. Adhesive: The adhesive cement or bond is applied in a layer that's 0.006m thick. The volume of adhesive applied per square metre is 0.0006 cubic metres per square metre. The density of the adhesive material is 1600 kilograms per cubic metre. To find out how much the adhesive weighs per square metre, we multiply the volume per square metre (0.006 m³/m²) by the material density (1600 kg/m³), which gives us 9.60 kg per square metre. We need to account for waste, so we add 5% to the total weight per square metre. 5% of 9.60 kilograms is 0.48 kilograms. The total weight per square metre, including 5% waste, is 9.60 + 0.48 = 10.08 kilograms. Each bag of adhesive weighs 20 kilograms. To figure out how many bags we need per square metre, we divide the weight of one bag (20 kg) by the total weight per square metre (10.08 kg). This gives us approximately 0.504 bags per square metre.

Total cost of materials used per square metre:

Tile- 0.88 per x 13,000.00= ₦11,440.00
Adhesive- 0.05184 bag x 8,000.00 = ₦414.72
Total cost of materials = ₦11,852.72

For the service required:

A Skilled Tiler, a Semi skilled Tiler and a Tile cutter charges ₦800.00/square metre.

Total cost:

The cost of fixing floor tile cement sand screeded bed for per square metre is includes the cost of materials and labour. Total Cost is the addition of ₦11,852.72 (Material costs) and ₦800.00 (Service cost) which gives a total of ₦12,852.72.

1.5.3. 13mm Thick Cement Sand Internal and External Wall Finish

In building construction, a 13mm thick cement-sand mixture serves as a crucial internal and external wall finish, enhancing structural integrity and aesthetic appeal. Applied meticulously, this coating provides a durable surface, shielding walls against environmental elements and wear. Internally, it creates a smooth, paintable canvas for interior design. Externally, it adds a protective layer, bolstering weather resistance and contributing to the building's overall durability. This application is pivotal in the superstructure phase, ensuring longevity and quality in both functional and visual aspects of the building.

Assumptions:

The tasks involves 13mm thick cement sand internal and external wall finish.
Mortar mix ratio: Cement to Sand is 1:3, 1 part cement to 4 parts sand, the mix consists of 4 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.

Calculations:

Materials for wall plaster composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg = 8.64 bags ≈ 9 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.3 cubic metres x 0.5 = 0.15 cubic metres. When converted to litres, 0.15 cubic metres x 1000 = 150 litres.

For the materials in the mortar per square metre:

The average bedding thickness for a plaster is of 13 mm (or 0.013 metres), the volume required per square metre is 0.013 m³/m².
The Cement for mortar, In 1 m³ of mortar, 9 bags of 50 kg each are required. For 0.013 m³/m², the amount of cement 0.013 m³/m² x 9 bags = 0.117 bags/m²
The required Sand for mortar, In 1 m³ of mortar, 1.440 tonnes of sand are required. For 0.036 m³/m², the amount of sand 0.013 m³ x 1.440 = 0.01872 tonnes
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.013 m³ of mortar: Amount of water 0.117m³ x 85.71litres = 10.03 litres.

Total cost of materials used per square metre

Cement- 0.117 bags x 7,700.00= ₦90.09
Sand- 0.01872 tonnes x 8,000.00 = ₦149.76
Total cost of materials = ₦239.85

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 25 m² per day): ₦8,500 / 25 m² = ₦340.00 per square metre.

Total cost:

The cost of cement sand wall plaster per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦2,908.72 (Material costs) and ₦340.00 (Service cost) which gives a total of ₦3,248.72.

1.5.4. Fix Wall Tiles on Roughened Internal Walls

In building construction, fixing wall tiles on roughened internal walls is crucial for durability and aesthetics. The process begins by preparing the surface, ensuring it's clean and free of debris. Next, a suitable adhesive, often cement-based, is applied evenly on the wall using a notched trowel. Tiles are then carefully placed onto the adhesive, ensuring proper spacing and alignment. Once set, grout is applied to fill the gaps between tiles, enhancing their stability and water resistance. Properly fixing wall tiles enhances the structural integrity and visual appeal of the building's interior.

Assumptions:

The task involves fixing floor tile on screeded floor finish
The tile size is 0.4 m x 0.25m, with 3 pieces per pack.
There is a 5% wastage on the tile used purchase
Water cement ratio: The water-cement ratio is 0.5
The bedding thickness of 36 mm

Calculations:

Materials used for wall tiles:

A. Tiles: The wall tile used are the 0.4 metres long and the 0.25 metres wide, each tile covers an area of 0.10 square metres, each package contains 18 tiles. So, the total area covered by one package is 18 tiles x 0.10 square metres per tile = 1.8 square metres. To accommodate for waste, we add 5% to the total area covered by one package. 5% of 1.8 square metres is 0.09 square metres. The total area covered by one package, including waste, is 1.8 + 0.09 = 1.89 square metres. To find out how many packages we need for 1 square metre of wall area, we divide 1 by the area covered by one package (1.89 square metres). This gives us approximately 0.53 packages per square metre.

B. Adhesive: The adhesive cement or bond is applied in a layer that's 0.025m thick. The volume of adhesive applied per square metre is 0.0025 cubic metres per square metre. The density of the adhesive material is 1600 kilograms per cubic metre. To find out how much the adhesive weighs per square metre, we multiply the volume per square metre (0.0025m³/m²) by the material density (1600 kg/m³), which gives us 4.00 kg per square metre. We need to account for waste, so we add 5% to the total weight per square metre. 5% of 4 kilograms is 0.2 kilograms. The total weight per square metre, including 5% waste, is 4+ 0.2 = 4.2 kilograms. Each bag of adhesive weighs 20 kilograms. To figure out how many bags we need per square metre, we divide the weight of one bag (20 kg) by the total weight per square metre (4.20 kg). This gives us approximately 0.21 bags per square metre.

Total cost of materials used per square metre:

Tile- 0.53 pack x 20,000.00= ₦10,600.00
Adhesive- 0.21 bag x 17,000.00 = ₦9,010.00
Total cost of materials = ₦19,610.00

For the service required:

A Skilled Tiler, a Semi skilled Tiler and a Tile cutter charges ₦800.00 per square metre.

Total cost:

The cost of fixing floor tile cement sand screeded bed for per square metre is includes the cost of materials and labour. Total Cost is the addition of ₦19,610.00 (Material costs) and ₦800.00 (Service cost) which gives a total of ₦20,410.00.

1.5.5. Install POP Ceiling Finishes to Prepared Surface

Installing POP ceiling finishes involves applying a smooth, plaster-like material (Plaster of Paris) onto a prepared surface, typically a ceiling framework. The surface must first be cleaned and primed to ensure adhesion. The POP is mixed to a consistent paste and applied in layers, smoothing it with trowels. Once dried, the surface is sanded to achieve a flawless finish. Finally, the ceiling is painted or treated for durability, providing an aesthetically appealing, sturdy result.

Assumptions:

The task installing POP finish to the ceiling.
The task involves installing a square meter of ceiling finish.
The door is installed by POP installers.
The time needed for installing 1 square metre of the ceiling board is estimated at 0.5 gang hours.

Calculations:

The price for the POP ceiling board is ₦12,000.00 per square meter. This is the base cost for covering a 1 square metre area. The cost of transporting the materials is calculated as 10% of the material cost, which in this case equals ₦1,200.00. In addition, a waste allowance of 5% of the material cost is added to cover any potential material losses during installation. This results in an additional cost of ₦600.00 for waste.
To get the total material cost, we combine the base material cost, the transportation cost, and the waste allowance. So, ₦12,000.00 + ₦1,200.00 + ₦600.00 gives a total material cost of ₦13,800.00.
Additionally, nails are required for the installation. For every square meter, 0.01 bags of nails are used. With nails priced at ₦13,500.00 per bag, the cost of nails for 1 square metre is ₦135.00.
The total material cost and the total fixing cost. This means ₦13,800.00 + ₦135.00 equals ₦13,935.00 for installing 1 square metre of POP ceiling board.

For the service required:

The labor required for this installation involves a skilled pop installer and a semi-skilled pop installer, and the labor rate is ₦1,750.00 per gang hour. The time needed for installing 1 square metre of the ceiling board is estimated at 0.5 gang hours, so the labor cost for this task amounts to ₦875.00.

Total cost

The total cost installing a metal panel door. Total Cost is the addition of₦13,935.00 (Material costs) and ₦875.00 (Service cost) which gives a total of ₦14,810.00 per square metre.

Superstructure - Roof

The roof is an essential element of the superstructure, providing protection from weather elements like rain, snow, and sun. It serves to enclose and protect the building’s interior, offering insulation and structural support. Roofs can vary in design, including flat, pitched, or vaulted, depending on the architectural requirements.

2.1. In-Situ Concrete Works

2.1.1 Install Reinforcement Bars in Roof beams/ Slabs / Gutters /Parapet Walls

In building construction, reinforcing bars are strategically placed within roof gutters or slabs as part of the superstructure process. These bars, typically made of steel, are positioned to enhance structural integrity and durability. They are meticulously arranged according to engineering specifications to withstand various loads and stresses, such as those imposed by weather conditions or building usage. Proper placement ensures optimal support, preventing potential deformities or collapse. This reinforcement technique is essential in ensuring the longevity and stability of the building's roof system, offering resilience against external forces over time.

Assumptions:

The task is to Install reinforcement steel bars in column and beams. The materials used are reinforcement steel bars and binding wires. The standard length of reinforcement steel bars is 12 metres. The steel bars have the different diameters ranging from 32mm to 8mm. The standard size of binding wire is 20kg per roll.

Calculations:

For Different sizes of reinforcement steel bars:

A. 32mm Steel bar:

Weight per metre: 6.318 kg
Weight per 12m bar: 6.318 kg/m x 12m = 75.816 kg
Number of bars per tonne: 1 tonne / 75.816 kg ≈ 13 bars

B. 25mm Steel Bar:

Weight per metre: 3.856 kg
Weight per 12m bar: 3.856 kg/m x 12m = 46.272 kg
Number of bars per tonne: 1 tonne / 46.272 kg ≈ 22 bars

C. 20mm Steel bar:

Weight per metre: 2.468 kg
Weight per 12m bar: 2.468 kg/m x 12m = 29.616 kg
Number of bars per tonne: 1 tonne / 29.616 kg ≈ 34 bars

D. 16mm Steel bar:

Weight per metre: 1.58 kg
Weight per 12m bar: 1.58 kg/m x 12m = 18.96 kg
Number of bars per tonnes: 1 tonne / 18.96 kg ≈ 53 bars

E. 12mm Steel Bar:

Weight per metre: 0.888 kg
Weight per 12m bar: 0.888 kg/m x 12m = 10.656 kg
Number of bars per ton: 1 tonnes / 10.656 kg ≈ 94 bars

F. 10mm Steel bar:

Weight per metre: 0.617 kg
Weight per 12m bar: 0.617 kg/m x 12m = 7.404 kg
Number of bars per ton: 1 tonnes / 7.404 kg ≈ 135 bars

G. 8mm Steel bar:

Weight per metre: 0.395 kg
Weight per 12m bar: 0.395 kg/m x 12m = 4.74 kg
Number of bars per ton: 1 tonnes / 4.74 kg ≈ 211 bars

2. Binding wire:

Weight per roll: 20 kg
Quantity required per ton of steel bars: 12 kg
Number of rolls required per tonne: 12 kg / 20 kg per roll = 0.6 rolls
Cost of binding wire per tonne of reinforcement bars: 42,000 x 0.6 = 25,200

Daily equipment rentals calculations:

Cutting machine: 50,000.00/day
Angle grinder: 25,000.00/day
Rebar bender (Electric): 150,000.00/day
Total equipment Cost: 225,000.00/day
Average productivity: 1 tonne/day
Equipment cost per tonne: 225,000.00

Service:

Iron bender skilled: 10,000.00/day
Iron bender semi-Skilled Placer: 7,500/day
Iron bender semi-Skilled: 7,500/day
Total service cost: 25,000.00/day
Average productivity: 1 tonnes/day
Service cost per tonne: 25,000.00

Total Installation cost per tonne:

This includes materials, equipment, and service costs. The exact cost depends on the size of the steel bars used. For example, if using 20mm steel bars:
Material Cost: Cost of steel bars ₦1,200,000.00 + (10% waste ₦120,000.00 )+ binding wire cost )
=(₦1,200,000.00+120,000.00+ ₦25,200)
=1,345,200.00
Total Cost per tonne = Material Cost + 225,000.00 (equipment) + 25,000.00 (service)
= ₦1,345,200.00+₦225,000.00+₦25,000.00
=₦1,595,200.00/tonne

Schedule for Installing Reinforcement Bars:

Assumed quantities: 1 tonne
Total material cost per tonne: ₦1,345,200.00
Equipment cost per tonne: ₦225,000.00
Service cost per tonne: ₦25,000.00
Built up rate per tonne: ₦1,595,200.00/tonne

2.1.2. Pour Concrete in Roof beams/ Slab / Gutter /Parapet wall

Pouring concrete into roof beams during superstructure construction involves meticulous planning and precise execution. After ensuring the formwork is securely in place and reinforcement bars are in place according to engineering designs, concrete is mixed to the required consistency and poured into the designated areas, typically utilizing pumps for higher elevations. Careful monitoring maintains the desired level and prevents air pockets. Once poured, the concrete undergoes curing to strengthen its integrity. This critical step forms a sturdy foundation for the roof structure, ensuring durability and stability for the entire building.

Assumptions:

Concrete Mix Composition:

The task involves pouring of concrete in 1 cubic metre of concrete in column base, column starter and concrete slab.
Ratio: Cement to Sand to Granite is 1:2:4.
Total Portions: The mix consists of 7 parts.
Void in Aggregates: There is a 54% void in the aggregates to account for material shrinkage and waste.
Mix Volumes: To prepare 1 cubic metre of wet concrete, 1.54 cubic metres of dry concrete is needed.
Water Cement Ratio: The water-cement ratio is 0.5.
The output of the Workers is 2 cubic metres daily.
The daily rental cost of a concrete mixer is ₦120,000.00.

Calculations:

Materials required:

C. Granite: The volume of granite required is 1.54 cubic metres x (4/7) = 0.88 cubic metres. To get the mass of Cement, we will multiply the volume by the density. The density of Sand is 1600 kg/m³. The density of granite is 1700 kg/m³. The mass of granite will be 0.88 cubic metres x 1700 kg/m³ = 1496 kg. The weight of granite in tonnes is 1472 kg / 1000 = 1.496 tonnes.

D. Water: The water cement ratio for concrete is 0.5. The volume required is 0.22 cubic metres x 0.5 = 0.11 cubic metres. When converted to litres, 0.11 cubic metres x 1000 = 110 litres.

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 2 cubic metres per day): ₦8,500 / 2 = ₦4,250 per cubic metre.

Equipment Used:

For the concrete mixer rental: The daily rental cost: ₦120,000.00. The daily production capacity is 2 cubic metres. The equipment cost per cubic metre: ₦120,000 / 2 = ₦60,000 per cubic metres.

Summary:

Materials per cubic metre:

Cement: 7 bags = 7 x 7,700 per bag =₦53,900.00
Sand: 0.704 tonnes = 0.704 x 8,000= ₦5,632.00
Granite: 1.496 tonnes= 1.496 x 13,000.00=₦19,448.00
Water: 110 litres
Total cost of materials =₦78,980.00

The total cost per cubic metre of concrete:

The total cost for pouring 1 cubic metre of concrete includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦78,980.00 (Material costs), ₦4,250.00 (Service cost) and ₦60,000.00(Equipment cost) which gives a total of ₦143,230.00.

Schedule for Pouring Concrete in Roof beams/ Slabs / Gutters / Parapet Walls:

Assumed quantities: 1 cubic metre
Total material cost per cubic metre: ₦78,980.00
Service or labour cost per cubic metre: ₦4,250.00
Equipment cost per cubic metre: ₦60,000.00
Built up rate per cubic metre: ₦143,230.00

2.1.3 Fix Formwork to Roof beams/ Slabs / Gutters / Parapet Walls

Fixing formwork to a roof slab or roof beams in building construction involves several steps. First, ensure the surface is clean and free of debris. Then, position the formwork panels securely along the edges of the gutter or slab, ensuring they are level and properly aligned. Use adjustable props or braces to support the formwork and maintain its position. Secure the formwork in place using nails or clamps, ensuring it is tightly fastened to prevent any movement during the pouring of concrete. Finally, inspect the setup for stability and make any necessary adjustments before pouring concrete into the formwork.

Assumptions:

The task involves fixing formwork to soffits of slab and beams. The proposed area to be covered by formwork is 120 square metres (m²). The length is 12 metres and breadth is 10 metres.
Sheathing is the platform that will receive the concrete work. It can steel, wooden plank or marine board
Stringer and Joist connect the sheathing with the shoring. It could be H-beams formwork or 2" x 3" (50x75mm) hardwood spaced at 600mm for wooden formwork.
Shoring is the vertical member that transfers the dead load of the concrete to another floor. It could be Steel pipes for steel formwork or bamboo spaced at 600mm for wooden formwork
The sheathing formwork to be used is Marine board and Hardwood, while the shoring material to be used is Bamboo.
Marine board size: 1.2 x 2.4 metres (2.88 m²), Hardwood size 50 x 75 x 3.6 metres
Cost per piece of marine boards: ₦11,000.00
Cost per piece of Hardwood: ₦650.00
The average length of a Bamboo is 6m. The assumed headroom height is 3m.
Circular saw is the equipment used.

Calculations:

The calculation for the stringers is as follows, the longer length is 12m, to determine the number of lines, we have 10m / 0.6m + 1 = 18 lines. The total length of Stringers will be 12m x 18 = 216m. To get the number hardwood pieces: 216m / 3.6m = 60 pieces.
The calculation for the Joist is as follows, the shorter length is 10m, to determine the number of lines will be 12m / 0.6m + 1 = 21 lines. The total length of Joist will be 10m x 21 = 210m. The number of hardwood pieces will be 210 / 3.6m = 58 pieces
The calculation for the shoring is as follows, the number of points where there will be Bamboo will be 18 lines x 21 lines = 378 points. The average length of a Bamboo is 6m. The assumed headroom height is 3m. The total length of shoring is 1137 metres. The number of bamboo required: 1137m / 6m = 189 pieces, which is approximated to 200 pieces for a load of Bamboo.

The cost calculations:

A. Marine board: the area of the size is (2.88 m²), to cover 120 metres square, 120 / 2.88 = 41.66, rounded up to 42 boards. The total cost for marine boards is 11 x ₦11,000.00 = ₦420,000.00.

B. Hardwood: 60 pieces of stringers and 58 pieces of joist would be used, 118 pieces of 50 x 75 x 3.60m hardwood is used, the total cost for 50 x 75 hardwood will be 118 x ₦450.00 = ₦53,100.00.

C. Nails: 0.25 kg of wire nails is used to nail per square metre as the constant, the total nails needed is 120 x 0.25 kg = 30 kg. The total cost for nails: 30 x ₦1,600.00 = ₦48,000.00.

D. Bamboo: A load of Bamboo costs ₦100,000.

Total material cost:

The total cost for the use of marine board as formwork is ₦420,000.00 (boards) + ₦53,100.00 (hardwood) + ₦48,000.00 (nails)
= ₦521,100.00.
The material cost per square metre: ₦521,100 / 120 m² = ₦4,342.50/m²
Assuming the formwork can be reused twice: ₦4,342.5 / 2 = ₦2,175.25/m²

For the service required:

A skilled Carpenter will charge ₦6,000 per day, while a semi-skilled carpenter is paid ₦3,000 per day. The total cost of labour is ₦9,000 per day. The labour output is 15 square metres per day, per square metre is ₦9,000 / 8 m² = ₦1,125.00/m²

Equipment used:

For the circular saw rental: The daily rental cost: ₦12,000.00. The daily production capacity is 15 m². The equipment cost per cubic metre is ₦12,000 / 8 m² = ₦1,500.00/m²

Total Cost:

The total cost for per square metre of fixing formwork to sides of concrete base, it includes the cost of materials, labour, and equipment. Total cost is the addition of the cost per square metre of material costs of ₦2,175.25/m², service cost of ₦1,125.00/m² and equipment cost ₦1,500.00/m² which gives a total of ₦4,800.25/m².

Schedule for Fixing Formwork to Roof beams/ Slabs / Gutters / Parapet Walls:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦2,175.25/m²
Material cost for two use case: ₦1,840.00/m²
Service or labour cost per square metre: ₦1,125.00/m²
Equipment cost per square metre: ₦1,500.00/m²
Built up rate per square metre: ₦4,800.25/m²

2.2. Carpentry

Carpentry in the roof phase of building construction involves the framing, support, and installation of the roof structure. This includes tasks like constructing roof trusses, rafters, beams, and supports, ensuring the framework is level and secure. It also covers sheathing installation, which forms the base layer for roofing materials. Carpentry ensures the roof is durable, weatherproof, and structurally sound to protect the building from external elements.

2.2.1. Install Rafters Treated Hardwood Roof Members / Carcass

In building construction, installing rafters involves several steps. First, determine the rafter layout according to the building plans. Next, cut the treated hardwood to specified lengths, ensuring precise measurements for structural integrity. Then, position each rafter in place, securing them to the wall plates and ridge beam using appropriate fasteners. Check alignment and spacing to ensure uniformity and stability. Finally, brace the rafters temporarily to maintain their position before adding additional roofing components. This process forms the essential framework of the roof, providing support for subsequent layers of insulation, sheathing, and roofing materials.

Assumptions:

The task involves the installation of treated hardwood rafters as roof members and carcass
Productivity output: 36 planks x 3.6 meters = 129.6 meters.

Calculations:

A. Rafter: The 50 x 75 x 3600mm hardwood timber, delivered to the site, costs ₦650 for each 3.6 meters of length. To find the price per metre, we divide ₦650 by 3.6, which gives a cost of ₦180.56 per metre. We account for the cost of lapping, which refers to the process of overlapping the timbers for additional strength. The cost of lapping is 60% of the per-metre cost, so we multiply ₦180.56 by 0.60, resulting in an additional ₦108.34 for lapping. Adding this to the original cost per metre, we get a total of ₦288.90 per metre.

To ensure enough material is available, we also need to account for waste, which is typically estimated at 20% of the material cost. To calculate this, we multiply ₦288.90 by 0.20, giving ₦57.78 for waste. Adding the waste to the previous total, the overall material cost, including waste, comes to ₦346.68 per metre.

B. Nails: A 20kg bag of nails costs ₦35,000, so the cost per kilogram is ₦1,750. For each meter of timber, approximately 0.045kg of nails are needed. To find the cost of nails per metre, we multiply 0.045kg by ₦1,750, which results in a cost of ₦78.75 per metre for nails.

To find the total material cost per metre, we add the cost of timber (including waste) and the cost of nails. This gives ₦346.68 + ₦78.75, for a total of ₦425.43 per meter for materials.

For the service required:

The labor required involves two carpenters and one semi-skilled worker, with a combined daily cost of ₦14,000. The team is capable of installing 36 planks, each measuring 3.6 meters, which totals 129.6 meters of timber installation per day. To find the labor cost per meter, we divide the daily wage of ₦14,000 by 129.6 meters, which results in a labor cost of ₦108.02 per metre.

For the Equipment:

A circular saw is required for cutting the timber, and renting the saw costs ₦12,000 per day. The team can process 15 square metres per day, so dividing ₦12,000 by 129.6 meters, the equipment cost per metre is ₦92.59.

Total cost

The total cost per meter of rafter installation. The material cost per metre is ₦425.43, the equipment cost per metre ₦92.59 and the service (labour) cost per metre is ₦108.02. Therefore, the total cost per meter of installing the timber rafters is ₦626.04.

2.2.2. Install Treated Kingpost & Strut Hardwood Roof Members / Carcass

Installation of treated kingpost and strut hardwood roof members in building construction involves several steps. First, assess the structural layout to determine precise placement. Then, securely fix the king post, typically a vertical timber, into position atop the supporting walls or beams. Next, install the horizontal struts, ensuring they are properly aligned and braced for stability. Carefully connect these components using appropriate fasteners, such as bolts or nails, to create a sturdy framework. Finally, inspect the assembly for any irregularities or deficiencies and make necessary adjustments to ensure structural integrity.

Assumptions:

The task involves the installation of treated hardwood rafters as roof members and carcass
Productivity output: 36 planks x 3.6 meters = 129.6 meters.

Calculations:

A. Kingpost: The 50 x 100 x 3600mm hardwood timber, delivered to the site, costs ₦1200 for each 3.6 meters of length. To find the price per metre, we divide ₦1200 by 3.6, which gives a cost of ₦333.33 per metre. We account for the cost of lapping, which refers to the process of overlapping the timbers for additional strength. The cost of lapping is 60% of the per-metre cost, so we multiply ₦333.33 by 0.60, resulting in an additional ₦199.99 for lapping. Adding this to the original cost per metre, we get a total of ₦533.32 per metre.

To ensure enough material is available, we also need to account for waste, which is typically estimated at 20% of the material cost. To calculate this, we multiply ₦533.32 by 0.20, giving ₦106.66 for waste. Adding the waste to the previous total, the overall material cost, including waste, comes to ₦639.98 per metre.

To find the total material cost per metre, we add the cost of timber (including waste) and the cost of nails. This gives ₦639.98 + ₦78.75, for a total of ₦718.73 per metre for materials.

For the service required:

The labor required involves two carpenters and one semi-skilled worker, with a combined daily cost of ₦14,000. The team is capable of installing 36 planks, each measuring 3.6 metres, which totals 129.6 metres of timber installation per day. To find the labor cost per meter, we divide the daily wage of ₦14,000 by 129.6 metres, which results in a labor cost of ₦108.02 per metre.

For the Equipment:

A circular saw is required for cutting the timber, and renting the saw costs ₦12,000 per day. The team can process 15 square metres per day, so dividing ₦12,000 by 129.6 meters, the equipment cost per metre is ₦92.59.

Total cost

The total cost per meter of rafter installation. The material cost per metre is ₦718.73, the equipment cost per metre ₦92.59 and the service (labour) cost per metre is ₦108.02. Therefore, the total cost per meter of installing the timber rafters is ₦1,437.36.

2.3. Sheet Roof Covering

In building construction, a sheet roof covering as part of the "superstructure - roof" refers to a protective layer installed on the roof structure to shield the interior from weather elements. It typically involves materials such as metal sheets, bituminous membranes, or fiberglass, providing durability, weather resistance, and thermal insulation. These coverings are attached to the roof framework, enhancing the building's overall strength and preventing water infiltration while maintaining the aesthetic appeal and functionality of the roof.

2.3.1. Install Roof Covering on Roof Carcass

In the superstructure phase of building construction, installing roof covering involves several key steps. First, ensuring the roof carcass is structurally sound and meets design specifications. Then, applying underlayment to provide a moisture barrier and enhance insulation. Next, laying down the chosen roofing material, such as shingles, tiles, or metal sheets, in accordance with manufacturer instructions and local building codes. Finally, sealing seams and edges to prevent water infiltration and ensuring proper drainage. This meticulous process ensures a durable and weather-resistant roof, crucial for the building's integrity and longevity.

Assumptions:

The task involves the installation of roof covering on hardwood members Carcass.

Calculations:

When installing aluminum roofing sheets with a 0.55 gauge, the cost is broken down into material expenses and labor charges. First, the material cost includes the aluminum roofing itself, priced at ₦1,800.00 per square meter. In addition, washers are required, with 7 pieces costing ₦84, and Screws also needed in the same quantity, costing ₦87.50 for 7 pieces.

Adding up the roofing sheet, washers, and screws, the total material cost per square meter comes to ₦1,971.50. Since there is always some material loss during installation, we include a 5% waste allowance. To calculate this, ₦1,971.50 is multiplied by 0.05, resulting in ₦98.58 for waste. Adding this waste factor brings the total material cost per square meter to ₦2,070.08.

For the service required:

We consider the service cost, which involves hiring two carpenters and one semi-skilled carpenter. The carpenters are paid ₦3,500 each, making a total of ₦7,000 for the carpenters, while the semi-skilled worker earns ₦2,000. Therefore, the total labor cost for a day comes to ₦9,000. With an output of 10 square meters per day, the labor cost per square meter is ₦900.00

Total cost:

The material cost per square meter is ₦2,070.08, and the labor cost per square meter is ₦900, bringing the total cost per square meter to ₦2,970.08. This amount represents the complete cost for installing aluminum roofing sheets, including both materials and labor.

2.4. Masonry

In construction procedures, masonry in the roof section typically involves building parapet walls, chimneys, and sometimes structural elements like load-bearing walls that extend to the roof. It includes the installation of coping stones, waterproofing layers over masonry surfaces, and flashing around penetrations to prevent water ingress. Masonry work ensures structural stability, weather resistance, and proper drainage. It may also involve detailing joints, insulation placement, and integration with roofing materials for a seamless, durable finish.

2.4.1. Lay 225 x 450mm Sandcrete Parapet Walls

Assumptions:

The task involves laying of sandcrete blocks for 1 square metre of parapet wall.
Mortar mix ratio: Cement to Sand is 1:6, 1 part cement to 6 parts sand, the mix consists of 7 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5.
Size of block in consideration is 450mmx 225mm x 225mm blocks

Calculations:

Materials for mortar composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg =4.93 bags ≈ 5 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.17 cubic metres x 0.5 = 0.085 cubic metres. When converted to litres, 0.85 cubic metres x 1000 = 85.71 litres.

The mortar is then added to the blocks with the dimensions 0.45 x 0.225 x 0.25 which give a volume of 0.02671875 m³ (V2). There is a void in the two sides in the block that is to be deducted is 2 x 0.15m x .15m x 0.025m=0.001125m³ (D1). The volume of mortar per block is mortar volume per block is the difference between V2 and (V1+D1)= 0.02278125 m³ - (0.02671875m³+ 0.001125m³) = 0.0028125m³/Block. There are 10 blocks in a square metre of block wall and the volume of mortar per square metre For 225 Blockworks is 0.028125 m³/m².

For the materials in the mortar per square metre

10 blocks of 225mm block wall are required per square metre.
The Cement for mortar, In 1 m³ of mortar, 4.937142857 bags of 50 kg each are required. For 0.028125 m³/m², the amount of cement 0.028125 m³ x 4.937142857 =0.13948 bags/m².
The required Sand for mortar, In 1 m³ of mortar, 1.64571 tonnes of sand are required. For 0.028125 m³/m², the amount of sand 0.028125 m³ x 1.64571 = 0.04631 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.028125 m³ of mortar: Amount of water 0.028125 m³ x 85.71litres = 2.4098 litres.

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 5.5 m² per day): ₦8,500 / 5.5 m² = ₦1,545.45 per square metre.

Total cost of materials used per square metre:

Blocks- 10 blocks make 1 square metre = 10 x 750= ₦7,500.00
Cement- 0.13948 bags x 7,700.00= ₦1,073.99
Sand- 0.04631 x tonnes x 8,000.00 = ₦370.48
Total cost of materials=₦8,944.47

Total cost:

The cost of laying an Sandcrete block wall per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦8,944.47 (Material costs) and ₦1,545.00 (Service cost) which gives a total of ₦10,489.92.

Schedule for Laying 225 x 450mm Sandcrete Parapet Walls:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦8,944.47
Service or labour cost per square metre: ₦1,545.00
Built up rate per square metre: ₦10,489.92

2.4.3. Lay 150 x 450mm Sandcrete Parapet Walls

Assumptions:

The task involves laying of sandcrete blocks for 1 square metre of parapet block wall.
Mortar mix ratio: Cement to Sand is 1:6, 1 part cement to 6 parts sand, the mix consists of 7 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5.
Size of block in consideration is 450mmx 150 mm x 225mm blocks

Calculations:

Materials for mortar composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg =4.93 bags ≈ 5 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.17 cubic metres x 0.5 = 0.085 cubic metres. When converted to litres, 0.85 cubic metres x 1000 = 85.71 litres.

For the materials in the mortar per square metre:

10 blocks of 225mm block wall are required per square metre.
The Cement for mortar, in 1 m³ of mortar, 4.937142857 bags of 50 kg each are required. For 0.028125 m³/m², the amount of cement 0.028125 m³ x 4.937142857 =0.13948 bags/m².
The required Sand for mortar, In 1 m³ of mortar, 1.64571 tonnes of sand are required. For 0.028125 m³/m², the amount of sand 0.028125 m³ x 1.64571 = 0.04631 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.028125 m³ of mortar: Amount of water 0.028125 m³ x 85.71litres = 2.4098 litres.

For the service required:

A skilled mason will charge ₦5,000.00 per day, while a semi-skilled mason is paid ₦3,500.00 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 5.5 m² per day): ₦8,500.00 / 5.5 m² = ₦1,545.45 per square metre.

Total cost of materials used per square metre

Blocks- 10 blocks makes 1 square metre = 10 x 650.00= ₦6,500.00
Cement- 0.13948 bags x 7,700.00= ₦1,073.99
Sand- 0.04631 x tonnes x 8,000.00 = ₦370.48
Total cost of materials=₦8,944.47

Total cost:

The cost of laying an sandcrete block wall per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦8,944.47 (Material costs) and ₦1,545.00 (Service cost) which gives a total of ₦10,489.92.

Schedule for Laying of 150 x 450mm Sandcrete Parapet Walls:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦8,944.47
Service or labour cost per square metre: ₦1,545.00
Built up rate per square metre: ₦10,489.92

Superstructure - Staircase

Staircase works within superstructure processes encompass the design, fabrication, and installation of stair systems in buildings. This includes structural analysis to ensure safety and compliance with building codes, material selection such as concrete, steel, or wood, and precise measurements for accurate fitting. Construction involves assembling steps, landings, and handrails with attention to aesthetic appeal and functionality. Integration of stairs into the building's framework requires coordination with other trades and adherence to architectural plans.

3.1. In-Situ Concrete Works

In-situ concrete works for the superstructure, specifically for staircases in building construction, involve pouring and forming concrete directly at the construction site. This includes creating the staircase's steps, landings, risers, and supporting beams. The process typically involves setting up formwork, reinforcement (steel bars), and ensuring proper curing for strength. It requires precise measurement, alignment, and finishing to ensure the staircase is stable, durable, and meets design specifications for both functionality and aesthetics.

3.1.1. Install Reinforcement Bars in Staircase

In building construction, laying reinforcement for a staircase superstructure involves precise steps. Initially, workers position steel bars or mesh within formwork to create the staircase's shape. These bars, typically arranged in a grid pattern, provide structural strength to withstand loads. Attention to detail is crucial, ensuring proper alignment and spacing according to engineering specifications. Once the reinforcement is in place, concrete is poured over it, encapsulating the bars to form a solid structure. This meticulous process ensures the staircase's durability and safety within the building framework.

Assumptions:

The task is to Install reinforcement steel bars in column and beams. The materials used are reinforcement steel bars and binding wires. The standard length of reinforcement steel bars is 12 metres. The steel bars have the different diameters ranging from 32mm to 8mm. The standard size of binding wire is 20kg per roll.

Calculations:

For Different sizes of reinforcement steel bars:

A. 32mm Steel bar:

Weight per metre: 6.318 kg
Weight per 12m bar: 6.318 kg/m x 12m = 75.816 kg
Number of bars per tonne: 1 tonne / 75.816 kg ≈ 13 bars

B. 25mm Steel Bar:

Weight per metre: 3.856 kg
Weight per 12m bar: 3.856 kg/m x 12m = 46.272 kg
Number of bars per tonne: 1 tonne / 46.272 kg ≈ 22 bars

C. 20mm Steel bar:

Weight per metre: 2.468 kg
Weight per 12m bar: 2.468 kg/m x 12m = 29.616 kg
Number of bars per tonne: 1 tonne / 29.616 kg ≈ 34 bars

D. 16mm Steel bar:

Weight per metre: 1.58 kg
Weight per 12m bar: 1.58 kg/m x 12m = 18.96 kg
Number of bars per tonnes: 1 tonne / 18.96 kg ≈ 53 bars

E. 12mm Steel Bar:

Weight per metre: 0.888 kg
Weight per 12m bar: 0.888 kg/m x 12m = 10.656 kg
Number of bars per ton: 1 tonnes / 10.656 kg ≈ 94 bars

F. 10mm Steel bar:

Weight per metre: 0.617 kg
Weight per 12m bar: 0.617 kg/m x 12m = 7.404 kg
Number of bars per ton: 1 tonnes / 7.404 kg ≈ 135 bars

G. 8mm Steel bar:

Weight per metre: 0.395 kg
Weight per 12m bar: 0.395 kg/m x 12m = 4.74 kg
Number of bars per ton: 1 tonnes / 4.74 kg ≈ 211 bars

2. Binding wire:

Weight per roll: 20 kg
Quantity required per ton of steel bars: 12 kg
Number of rolls required per tonne: 12 kg / 20 kg per roll = 0.6 rolls
Cost of binding wire per tonne of reinforcement bars: 42,000 x 0.6 = 25,200

Daily equipment rentals calculations:

Cutting machine: 50,000.00/day
Angle grinder: 25,000.00/day
Rebar bender (Electric): 150,000.00/day
Total equipment Cost: 225,000.00/day
Average productivity: 1 tonnes/day
Equipment cost per tonne: 225,000.00

Service:

Iron bender skilled: 10,000.00/day
Iron bender semi-Skilled Placer: 7,500/day
Iron bender semi-Skilled: 7,500/day
Total service cost: 25,000.00/day
Average productivity: 1 tonnes/day
Service cost per tonne: 25,000.00

Total Installation cost per tonne:

This includes materials, equipment, and service costs. The exact cost depends on the size of the steel bars used. For example, if using 20mm steel bars:
Material Cost: Cost of steel bars ₦1,200,000.00 + (10% waste ₦120,000.00 )+ binding wire cost )
=(₦1,200,000.00+120,000.00+ ₦25,200)
=1,345,200.00
Total Cost per tonne = Material Cost + 225,000.00 (equipment) + 25,000.00 (service)
= ₦1,345,200.00+₦225,000.00+₦25,000.00
=₦1,595,200.00/tonne.

Schedule for Installing Reinforcement Bars in Staircase:

Assumed quantities: 1 tonne
Total material cost per tonne: ₦1,345,200.00
Equipment cost per tonne: ₦225,000.00
Service cost per tonne: ₦25,000.00
Built up rate per tonne: ₦1,595,200.00/tonne

3.1.2. Fix Formwork to Staircase

Fixing formwork to concrete in the staircase part of a superstructure involves several steps. First, measure and cut the formwork to the required dimensions of the staircase. Securely fix the formwork in place, ensuring it aligns with the design specifications. Reinforce it with bracing to prevent movement during concrete pouring. Apply a release agent to facilitate easy removal later. Pour the concrete carefully, ensuring it fills all spaces and achieves the desired shape. After the concrete cures, remove the formwork, revealing the finished staircase structure

Assumptions:

The task involves fixing formwork to soffits of slab and beams. The proposed area to be covered by formwork is 120 square metres (m²). The length is 12 metres and breadth is 10 metres.
Sheathing is the platform that will receive the concrete work. It can steel, wooden plank or marine board
Stringer and Joist connect the sheathing with the shoring. It could be H-beams formwork or 2" x 3" (50x75mm) hardwood spaced at 600mm for wooden formwork.
Shoring is the vertical member that transfers the dead load of the concrete to another floor. It could be Steel pipes for steel formwork or bamboo spaced at 600mm for wooden formwork
The sheathing formwork to be used is Marine board and Hardwood, while the shoring material to be used is Bamboo.
Marine board size: 1.2 x 2.4 metres (2.88 m²), Hardwood size 50 x 75 x 3.6 metres
Cost per piece of marine boards: ₦11,000.00
Cost per piece of Hardwood: ₦650.00
The average length of a Bamboo is 6m. The assumed headroom height is 3m.
Circular saw is the equipment used.

Calculations:

The calculation for the Stringers is as follows, the longer length is12m, to determine the number of lines; 10m / 0.6m + 1 = 18 lines. The total length of Stringers will be 12m x 18 = 216m. To get the number hardwood pieces; 216m / 3.6m = 60 pieces.
The calculation for the Joist is as follows, the shorter length is 10m, to determine the number of lines will be 12m / 0.6m + 1 = 21 lines. The total length of Joist will be 10m x 21 = 210m. The number of hardwood pieces will be 210 / 3.6m = 58 pieces.
The calculation for the shoring is as follows, the number of points where there will be Bamboo will be 18 lines x 21 lines = 378 points. The average length of a Bamboo is 6m. The assumed headroom height is 3m. The total length of shoring is 1137 metres. The number of bamboo required: 1137m / 6m = 189 pieces, which is approximated to 200 pieces for a load of Bamboo.

The cost calculations:

A. Marine board: the area of the size is (2.88 m²), to cover 120 metres square, 120 / 2.88 = 41.66, rounded up to 42 boards. The total cost for marine boards is 11 x ₦11,000.00 = ₦420,000.00

B. Hardwood: 60 pieces of stringers and 58 pieces of joist would be used, 118 pieces of 50 x 75 x 3.60m hardwood is used, the total cost for 50 x 75 hardwood will be 118 x ₦450.00 = ₦53,100.00

C. Nails: 0.25 kg of wire nails is used to nail per square metre as the constant, the total nails needed is 120 x 0.25 kg = 30 kg. The total cost for nails: 30 x ₦1,600.00 = ₦48,000.00

D. Bamboo: A load of Bamboo costs ₦100,000.

Total material cost:

The total cost for the use of marine board as formwork is ₦420,000.00 (boards) + ₦53,100.00 (hardwood) + ₦48,000.00 (nails)
= ₦521,100.00.
The material cost per square metre: ₦521,100 / 120 m² = ₦4,342.50/m²
Assuming the formwork can be reused twice: ₦4,342.5 / 2 = ₦2,175.25/m²

For the service required:

A skilled Carpenter will charge ₦6,000 per day, while a semi-skilled carpenter is paid ₦3,000 per day. The total cost of labour is ₦9,000 per day. The labour output is 15 square metres per day, per square metre is ₦9,000 / 8 m² = ₦1,125.00/m²

Equipment used:

For the circular saw rental: The daily rental cost: ₦12,000.00. The daily production capacity is 15 m². The equipment cost per cubic metre is ₦12,000 / 8 m² = ₦1,500.00/m²

Total Cost:

The total cost for per square metre of fixing formwork to sides of concrete base, it includes the cost of materials, labour, and equipment. Total cost is the addition of the cost per square metre of material costs of ₦2,175.25/m², service cost of ₦1,125.00/m² and equipment cost ₦1,500.00/m² which gives a total of ₦4,800.25/m².

Schedule for Fixing Formwork to Staircase:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦2,175.25/m²
Material cost for two use case: ₦1,840.00/m²
Service or labour cost per square metre: ₦1,125.00/m²
Equipment cost per square metre: ₦1,500.00/m²
Built up rate per square metre: ₦4,800.25/m²

3.1.3. Pour Concrete into Staircase

After the formwork has been meticulously set to define the stair's shape and dimensions, and reinforcement bars have been placed to fortify the structure against stress, concrete is carefully poured, filling the formwork to create the stairs' framework. Vibrators are employed to eliminate air bubbles and ensure even distribution. Once the concrete sets, the formwork is removed, unveiling the solid staircase. This process is crucial for ensuring structural integrity and functionality, contributing to the building's overall strength and usability.

Assumptions:

Concrete Mix Composition:

The task involves pouring of concrete in 1 cubic metre of concrete in column base, column starter and concrete slab.
Ratio: Cement to Sand to Granite is 1:2:4.
Total Portions: The mix consists of 7 parts.
Void in Aggregates: There is a 54% void in the aggregates to account for material shrinkage and waste.
Mix Volumes: To prepare 1 cubic metre of wet concrete, 1.54 cubic metres of dry concrete is needed.
Water Cement Ratio: The water-cement ratio is 0.5.
The output of the Workers is 2 cubic metres daily.
The daily rental cost of a concrete mixer is ₦120,000.00.

Calculations:

Materials required:

B. Sand: The volume of sand required is 1.54 cubic metres x (2/7) = 0.44 cubic metres. The density of Sand is 1600 kg/m³. To get the mass of Sand, we will multiply the volume by the density. The density of Sand is 1600 kg/m³. The mass of sand will be 0.44 cubic metres x 1600 kg/m³ = 704 kg. The weight of Sand in tonnes is 704 kg / 1000 =0. 704 tonne.

C. Granite: The volume of granite required is 1.54 cubic metres x (4/7) = 0.88 cubic metres. To get the mass of Cement, we will multiply the volume by the density. The density of Sand is 1600 kg/m³. The density of granite is 1700 kg/m³. The mass of granite will be 0.88 cubic metres x 1700 kg/m³ = 1496 kg. The weight of granite in tonnes is 1472 kg / 1000 = 1.496 tonnes.

D. Water: The water cement ratio for concrete is 0.5. The volume required is 0.22 cubic metres x 0.5 = 0.11 cubic metres. When converted to litres, 0.11 cubic metres x 1000 = 110 litres.

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 2 cubic metres per day): ₦8,500 / 2 = ₦4,250 per cubic metre.

Equipment Used:

For the concrete mixer rental: The daily rental cost: ₦120,000.00. The daily production capacity is 2 cubic metres. The equipment cost per cubic metre: ₦120,000 / 2 = ₦60,000 per cubic metres

Summary:

Materials per cubic metre:

Cement: 7 bags = 7 x 7,700 per bag =₦53,900.00
Sand: 0.704 tonnes = 0.704 x 8,000= ₦5,632.00
Granite: 1.496 tonnes= 1.496 x 13,000.00=₦19,448.00
Water: 110 litres
Total cost of materials =₦78,980.00

The total cost per cubic metre of concrete:

The total cost for pouring 1 cubic metre of concrete includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦78,980.00 (Material costs), ₦4,250.00 (Service cost) and ₦60,000.00(Equipment cost) which gives a total of ₦143,230.00.

Schedule for Pouring Concrete into Staircase:

Assumed quantities: 1 cubic metre
Total material cost per cubic metre: ₦78,980.00
Service or labour cost per cubic metre: ₦4,250.00
Equipment cost per cubic metre: ₦60,000.00
Built up rate per cubic metre: ₦143,230.00

3.2. Floor, Wall, Ceiling and Roof Finishings

In building construction, the staircase includes finishes for the floor, walls, ceiling, and roof within the staircase area. Floor finishes typically cover materials like tiles, wood, or concrete. Wall finishes may include paint, plaster, or cladding. Ceiling finishes involve materials such as gypsum board or suspended ceilings. The roof finish refers to any coverings above the staircase, like waterproofing or insulation, ensuring both aesthetics and functional protection within the staircase space.

3.2.1. Lay Cement Sand Screeded Bed on Staircase

In building construction, applying a cement sand screed bed on a staircase involves evenly spreading a mixture of cement and sand over the staircase steps to create a smooth, level surface. This process ensures proper leveling and a robust base for the final floor finish. The screed bed is crucial for achieving desired heights and providing a solid, durable layer that can withstand daily foot traffic. This step is part of the superstructure processes, contributing to the staircase's overall strength and durability while enhancing its aesthetic appeal.

Assumptions:

The task involves laying cement sand screeded bed on staircase
Mortar mix ratio: Cement to Sand is 1:3, 1 part cement to 4 parts sand, the mix consists of 4 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5
The bedding thickness of 36 mm

Calculations:

Materials for screeded bed composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg = 8.64 bags ≈ 9 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.3 cubic metres x 0.5 = 0.15 cubic metres. When converted to litres, 0.15 cubic metres x 1000 = 150 litres.

For the materials in the mortar per square metre:

The average bedding thickness for a bedding thickness of 36 mm (or 0.036 metres), the volume required per square metre is 0.036 m³/m².
The Cement for mortar, In 1 m³ of mortar, 9 bags of 50 kg each are required. For 0.036 m³/m², the amount of cement 0.036 m³/m² x 9 bags = 0.324 bags/m².
The required Sand for mortar, In 1 m³ of mortar, 1.440 tonnes of sand are required. For 0.036 m³/m², the amount of sand 0.036 m³ x 1.440 = 0.05184 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.036 m³ of mortar: Amount of water 0.036 m³ x 85.71litres = 2.4098 litres.

Total cost of materials used per square metre:

Cement- 0.324 bags x 7,700.00= ₦2,494.00
Sand- 0.05184 tonnes x 8,000.00 = ₦414.72
Total cost of materials = ₦2,908.72

For the service required:

A skilled mason will charge ₦5,000.00 per day, while a semi-skilled mason is paid ₦3,500.00 per day. The total cost of labour is ₦8,500.00 per day. The labour cost per cubic metre (assuming 25 m² per day): ₦8,500 / 25 m² = ₦340.00 per square metre.

Total cost of materials used per square metre

Cement- 0.324 bags x 7,700.00= ₦2,494.00
Sand- 0.05184 tonnes x 8,000.00 = ₦414.72
Total cost of materials = ₦2,908.72

Total cost:

The cost of laying cement sand screeded bed for floor finish per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦2,908.72 (Material costs) and ₦340.00 (Service cost) which gives a total of ₦3,248.72.

Schedule for Laying Cement Sand Screeded Bed on Staircase:

Assumed quantities: 1 square metre
Total material square metre: ₦2,908.72
Service or labour square metre: ₦340.00
Built up rate square metre: ₦3,248.72

3.2.2. Install Tile Floor Finish on Staircase

Staircase elegance takes shape! After prepping the treads and risers, thinset mortar, a sticky cement layer, is applied. Tiles are meticulously placed, starting from the top and working down. Precise leveling ensures a safe and comfortable walk. Risers are tackled next, with tiles cut to fit snug against treads. A special grout fills the gaps between tiles, creating a uniform look. Once cured, the floor is polished, revealing a beautiful, durable tiled staircase that enhances the building's aesthetics and functionality.

Assumptions:

The tasks involves fixing floor tile on screeded floor finish
The tile size is 0.6 mx 0.6m, with 3 pieces per pack.
There is a 5% wastage on the tile used purchase
Water cement ratio: The water-cement ratio is 0.5
The bedding thickness of 36 mm

Calculations:

Materials used for floor tiles:

Total cost of materials used per square metre

Tile- 0.88 per x 13,000.00= ₦11,440.00
Adhesive- 0.05184 bag x 8,000.00 = ₦414.72
Total cost of materials = ₦11,852.72

For the service required:

A Skilled Tiler, a Semi skilled Tiler and a Tile cutter charges ₦800.00/square metre.

Total cost:

The cost of fixing floor tile cement sand screeded bed for per square metre is includes the cost of materials and labour. Total Cost is the addition of ₦11,852.72 (Material costs) and ₦800.00 (Service cost) which gives a total of ₦12,852.72.

3.2.3. Apply Cement Sand Finish on Staircase

In building construction, applying a cement sand finish on staircases is vital for both aesthetic appeal and durability. After constructing the staircase framework, skilled workers meticulously spread a mixture of cement and sand over the steps, ensuring a smooth and level surface. They then employ specialized tools to refine the finish, smoothing out imperfections and creating a uniform texture. This process not only enhances the visual appeal of the staircase but also provides a robust surface resistant to wear and tear, ensuring longevity and safety for occupants.

Assumptions:

The task involves applying 13mm thick cement sand finish on staircases.
Mortar mix ratio: Cement to Sand is 1:3, 1 part cement to 4 parts sand, the mix consists of 4 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.

Calculations:

Materials for wall plaster composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg = 8.64 bags ≈ 9 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.3 cubic metres x 0.5 = 0.15 cubic metres. When converted to litres, 0.15 cubic metres x 1000 = 150 litres.

For the materials in the mortar per square metre

The average bedding thickness for a plaster is of 13 mm (or 0.013 metres), the volume required per square metre is 0.013 m³/m².
The Cement for mortar, in 1 m³ of mortar, 9 bags of 50 kg each are required. For 0.013 m³/m², the amount of cement 0.013 m³/m² x 9 bags = 0.117 bags/m².
The required Sand for mortar, in 1 m³ of mortar, 1.440 tonnes of sand are required. For 0.036 m³/m², the amount of sand 0.013 m³ x 1.440 = 0.01872 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.013 m³ of mortar: Amount of water 0.117m³ x 85.71litres = 10.03 litres.

Total cost of materials used per square metre:

Cement- 0.117 bags x 7,700.00= ₦90.09
Sand- 0.01872 tonnes x 8,000.00 = ₦149.76
Total cost of materials = ₦239.85

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 25 m² per day): ₦8,500 / 25 m² = ₦340.00 per square metre.

Total cost:

The cost of cement sand wall plaster per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦2,908.72 (Material costs) and ₦340.00 (Service cost) which gives a total of ₦3,248.72.

Entity - Barrier - Fence

Superstructure processes in fence construction involve tasks above ground level, focusing on the installation and assembly of structural components. These include laying of block wall, setting up posts, attaching horizontal rails, and securing vertical pickets or panels. The process ensures stability, alignment, and proper spacing of fence elements. Additionally, it includes adding finishing elements like caps, gates, and hardware. Superstructure work emphasizes durability, aesthetic appeal, and functionality, contributing to the fence's overall integrity and performance.

1. In-Situ Concrete Works

In-situ concrete refers to concrete that is mixed, poured, and cured directly at the construction site. It is used for the creation of strong, continuous structural elements such as foundations, walls, and slabs, tailored precisely to the design specifications of the building. It provides flexibility in shaping complex forms and integrates well with other construction processes. In-situ concrete ensures robust, monolithic structures, contributing to the overall stability and durability of the building while allowing for customized architectural features.

1.1. Install Reinforcement Bars in Fence Columns

Assumptions:

The task is to Install reinforcement steel bars in column and beams. The materials used are reinforcement steel bars and binding wires. The standard length of reinforcement steel bars is 12 metres. The steel bars have the different diameters ranging from 32mm to 8mm. The standard size of binding wire is 20kg per roll.

Calculations:

For Different sizes of reinforcement steel bars:

A. 32mm Steel bar:

Weight per metre: 6.318 kg
Weight per 12m bar: 6.318 kg/m x 12m = 75.816 kg
Number of bars per tonne: 1 tonne / 75.816 kg ≈ 13 bars

B. 25mm Steel Bar:

Weight per metre: 3.856 kg
Weight per 12m bar: 3.856 kg/m x 12m = 46.272 kg
Number of bars per tonne: 1 tonne / 46.272 kg ≈ 22 bars

C. 20mm Steel bar:

Weight per metre: 2.468 kg
Weight per 12m bar: 2.468 kg/m x 12m = 29.616 kg
Number of bars per tonne: 1 tonne / 29.616 kg ≈ 34 bars

D. 16mm Steel bar:

Weight per metre: 1.58 kg
Weight per 12m bar: 1.58 kg/m x 12m = 18.96 kg
Number of bars per tonnes: 1 tonne / 18.96 kg ≈ 53 bars

E. 12mm Steel Bar:

Weight per metre: 0.888 kg
Weight per 12m bar: 0.888 kg/m x 12m = 10.656 kg
Number of bars per ton: 1 tonnes / 10.656 kg ≈ 94 bars

F. 10mm Steel bar:

Weight per metre: 0.617 kg
Weight per 12m bar: 0.617 kg/m x 12m = 7.404 kg
Number of bars per ton: 1 tonnes / 7.404 kg ≈ 135 bars

G. 8mm Steel bar:

Weight per metre: 0.395 kg
Weight per 12m bar: 0.395 kg/m x 12m = 4.74 kg
Number of bars per ton: 1 tonnes / 4.74 kg ≈ 211 bars

2. Binding wire:

Weight per roll: 20 kg
Quantity required per ton of steel bars: 12 kg
Number of rolls required per tonne: 12 kg / 20 kg per roll = 0.6 rolls
Cost of binding wire per tonne of reinforcement bars: 42,000 x 0.6 = 25,200

Daily equipment rentals calculations:

Cutting machine: 50,000.00/day
Angle grinder: 25,000.00/day
Rebar bender (Electric): 150,000.00/day
Total equipment Cost: 225,000.00/day
Average productivity: 1 tonne/day
Equipment cost per tonne: 225,000.00

Service:

Iron bender skilled: 10,000.00/day
Iron bender semi-Skilled Placer: 7,500/day
Iron bender semi-Skilled: 7,500/day
Total service cost: 25,000.00/day
Average productivity: 1 tonne/day
Service cost per tonne: 25,000.00

Total Installation cost per tonne:

This includes materials, equipment, and service costs. The exact cost depends on the size of the steel bars used. For example, if using 20mm steel bars:
Material Cost: Cost of steel bars ₦1,200,000.00 + (10% waste ₦120,000.00 )+ binding wire cost )
=(₦1,200,000.00+120,000.00+ ₦25,200)
=1,345,200.00
Total Cost per tonne = Material Cost + 225,000.00 (equipment) + 25,000.00 (service)
= ₦1,345,200.00+₦225,000.00+₦25,000.00
=₦1,595,200.00/tonne

Schedule for Installing Reinforcement Bars:

Assumed quantities: 1 tonne
Total material cost per tonne: ₦1,345,200.00
Equipment cost per tonne: ₦225,000.00
Service cost per tonne: ₦25,000.00
Built up rate per tonne: ₦1,595,200.00/tonne

2. Masonry

Masonry in fence construction processes involves using materials like bricks, stones, and concrete blocks to create load-bearing and non-load-bearing walls, chimneys, fireplaces, and facades, and other structural elements above the foundation. It encompasses laying units in specific patterns with mortar to ensure stability, strength, and aesthetic appeal. Masonry work requires precision to maintain structural integrity, proper alignment, and adherence to building codes. It also involves installing reinforcement, controlling moisture, and providing insulation to enhance the durability and functionality of the superstructure.

2.1. Lay 225 x 450mm Sandcrete Block Wall

Assumptions:

The task involves laying of sandcrete blocks for 1 square metre of block wall.
Mortar mix ratio: Cement to Sand is 1:6, 1 part cement to 6 parts sand, the mix consists of 7 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5.
Size of block in consideration is 450mmx 225mm x 225mm blocks.

Calculations:

Materials for mortar composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg =4.93 bags ≈ 5 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.17 cubic metres x 0.5 = 0.085 cubic metres. When converted to litres, 0.85 cubic metres x 1000 = 85.71 litres.

For the materials in the mortar per square metre:

10 blocks of 225mm block wall are required per square metre.
The Cement for mortar, In 1 m³ of mortar, 4.937142857 bags of 50 kg each are required. For 0.028125 m³/m², the amount of cement 0.028125 m³ x 4.937142857 =0.13948 bags/m².
The required Sand for mortar, In 1 m³ of mortar, 1.64571 tonnes of sand are required. For 0.028125 m³/m², the amount of sand 0.028125 m³ x 1.64571 = 0.04631 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.028125 m³ of mortar: Amount of water 0.028125 m³ x 85.71litres = 2.4098 litres.

For the service required:

A skilled mason will charge ₦5,000 per day, while a semi-skilled mason is paid ₦3,500 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 5.5 m² per day): ₦8,500 / 5.5 m² = ₦1,545.45 per square metre.

Total cost of materials used per square metre:

Blocks- 10 blocks makes 1 square metre = 10 x 750= ₦7,500.00
Cement- 0.13948 bags x 7,700.00= ₦1,073.99
Sand- 0.04631 x tonnes x 8,000.00 = ₦370.48
Total cost of materials=₦8,944.47

Total cost:

Schedule for Laying of 225 x 450mm Sandcrete Block Wall:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦8,944.47
Service or labour cost per square metre: ₦1,545.00
Built up rate per square metre: ₦10,489.92

2.2. Lay 150 x 450mm Sandcrete Block Wall

Assumptions:

The task involves laying of sandcrete blocks for 1 square metre of block wall.
Mortar mix ratio: Cement to Sand is 1:6, 1 part cement to 6 parts sand, the mix consists of 7 parts.
Void in aggregates: There is a 20% void in the sand to account for material shrinkage and waste.
Mix volumes: To prepare 1 cubic metre of wet Mortar, 1.20 cubic metres of dry mortar is needed.
Water cement ratio: The water-cement ratio is 0.5.
Size of block in consideration is 450mmx 150 mm x 225mm blocks

Calculations:

Materials for mortar composition:

The number of bags of cement is (50 kg each): 246.86 kg / 50 kg =4.93 bags ≈ 5 bags.

C. Water: The water cement ratio for concrete is 0.5. The volume required is 0.17 cubic metres x 0.5 = 0.085 cubic metres. When converted to litres, 0.85 cubic metres x 1000 = 85.71 litres.

For the materials in the mortar per square metre:

10 blocks of 225mm block wall are required per square metre.
The Cement for mortar, in 1 m³ of mortar, 4.937142857 bags of 50 kg each are required. For 0.028125 m³/m², the amount of cement 0.028125 m³ x 4.937142857 =0.13948 bags/m².
The required Sand for mortar, In 1 m³ of mortar, 1.64571 tonnes of sand are required. For 0.028125 m³/m², the amount of sand 0.028125 m³ x 1.64571 = 0.04631 tonnes.
The required water for mortar, for 1 m³ of mortar, approximately 85.71 litres of water are needed, For 0.028125 m³ of mortar: Amount of water 0.028125 m³ x 85.71litres = 2.4098 litres.

For the service required:

A skilled mason will charge ₦5,000.00 per day, while a semi-skilled mason is paid ₦3,500.00 per day. The total cost of labour is ₦8,500 per day. The labour cost per cubic metre (assuming 5.5 m² per day): ₦8,500.00 / 5.5 m² = ₦1,545.45 per square metre.

Total cost of materials used per square metre:

Blocks- 10 blocks make 1 square metre = 10 x 650.00= ₦6,500.00
Cement- 0.13948 bags x 7,700.00= ₦1,073.99
Sand- 0.04631 x tonnes x 8,000.00 = ₦370.48
Total cost of materials=₦8,944.47

Total cost

The cost of laying sandcrete block wall per square metre is includes the cost of materials, labour, and equipment. Total Cost is the addition of ₦8,944.47 (Material costs) and ₦1,545.00 (Service cost) which gives a total of ₦10,489.92.

Schedule for Laying 150 x 450mm Sandcrete Block Wall:

Assumed quantities: 1 square metre
Total material cost per square metre: ₦8,944.47
Service or labour cost per square metre: ₦1,545.00
Built up rate per square metre: ₦10,489.92

Substructure Works

Superstructure Works

Entity - Detached Duplex, Bungalow and Apartment Block

Superstructure - Floor

1.1. In-Situ Concrete Works

1.1.1. Reinforcement Bars in Columns / Beams / Slab

1.1.2. Fix Formwork to Columns

1.1.3. Fix Formwork in Slabs and Beams

1.1.4. Pour Concrete to Columns / Beams / Slabs

1.2. Masonry

1.2.1. Lay 225 x 450mm Sandcrete Block Wall

1.2.2. Lay 150 x 450mm Sandcrete block wall in Superstructure

1.3. Doors and Windows

1.3.1. Install Doors

1.3.2. Install Windows

1.4. Metal Work

1.4.1. Install Burglary Proof

1.5. Floor, Wall, Ceiling and Roof Finishings

1.5.1. Cement Sand Screeded Bed for Floor Finish

1.5.2 fix floor tile on screeded floor finish

1.5.3. 13mm Thick Cement Sand Internal and External Wall Finish

1.5.4. Fix Wall Tiles on Roughened Internal Walls

1.5.5. Install POP Ceiling Finishes to Prepared Surface

Superstructure - Roof

2.1. In-Situ Concrete Works

2.1.1 Install Reinforcement Bars in Roof beams/ Slabs / Gutters /Parapet Walls

2.1.2. Pour Concrete in Roof beams/ Slab / Gutter /Parapet wall

2.1.3 Fix Formwork to Roof beams/ Slabs / Gutters / Parapet Walls

2.2. Carpentry

2.2.1. Install Rafters Treated Hardwood Roof Members / Carcass

2.2.2. Install Treated Kingpost & Strut Hardwood Roof Members / Carcass

2.3. Sheet Roof Covering

2.3.1. Install Roof Covering on Roof Carcass

2.4. Masonry

2.4.1. Lay 225 x 450mm Sandcrete Parapet Walls

2.4.3. Lay 150 x 450mm Sandcrete Parapet Walls

Superstructure - Staircase

3.1. In-Situ Concrete Works

3.1.1. Install Reinforcement Bars in Staircase

3.1.2. Fix Formwork to Staircase

3.1.3. Pour Concrete into Staircase

3.2. Floor, Wall, Ceiling and Roof Finishings

3.2.1. Lay Cement Sand Screeded Bed on Staircase

3.2.2. Install Tile Floor Finish on Staircase

3.2.3. Apply Cement Sand Finish on Staircase

Entity - Barrier - Fence

1. In-Situ Concrete Works

1.1. Install Reinforcement Bars in Fence Columns

2. Masonry

2.1. Lay 225 x 450mm Sandcrete Block Wall

2.2. Lay 150 x 450mm Sandcrete Block Wall