Common construction items in Nigeria and their quantity per unit of their measurement rates - (2023)

Introduction

Construction works involve a lot of measurement. The materials used in construction are sold in the market based on unit quantities and these unit quantities have unit prices. Accurate estimation of construction cost involves accurate measurement of construction quantities. In this post I would show how to accurately estimate unit quantity of five common construction materials. With these unit quantities one can get total quantity required, append unit price and get the total overall project sum. This post would be of assistance to beginners in quantity surveying and civil engineering as well as practicing engineers. It is not to replace their task. It would only show unit quantities. How to get the overall quantity, determine and append unit price cannot be done without expertise in this field.

The quantities to be estimated are:

  1. Blockwork
  2. Mortar for block laying and plastering
  3. Concrete work
  4. Reinforcement

Determination of block quantity

In Nigeria, there are about six (6) classes of block made from usually (1:6) mix ratio of cement: sand. The usual block sizes are as shown blow in the order of Length x Width x Breadth. These blocks can be hollow or solid depending on demand.

  1. 450 mm (18 inches) x 225 mm (9 inches) x 225 mm (9 inches)
  2. 450 x 200 x 225
  3. 450 x 150 x 225
  4. 450 x 125 x 225
  5. 450 x 100 x 225
  6. 450 x 75 x 225

Among these lists, 450 x 225 x 225 and 450 x 150 x 225 whether hollow or solid are commonest in building construction in Nigeria. Blocks are jointed together by mortar which usually have a thickness of 25 mm (1 inch) but this thickness can vary and the variation should be considered in determining mortar volume for work. In determining the area of block within an area of wall, the mortar thickness is necessarily considered.

Ideally, the area of a 450 x 225 mm block embedded in 25 mm mortar joints on all sides should be:

(25/2 + 450 + 25/2 ) x (25/2 + 225 + 25/2) = (12.5 + 450 + 12.5) x (12.5 + 225 + 12.5) = 475 x 250 = 118750 mm2 (0.11875 m2) instead of 450 x 225 (101250 mm2 or 0.101250 m2).

To determine number of blocks in 1 m2 of wall, then = 8.42 blocks

Adding 10% as waste, we have 8.42 + 0.842 = 9.262, say 10 blocks. Thus, we have 10 blocks in 1 m2 of wall

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Determination of mortar for laying and bedding blocks

The mortar for laying and bedding block is measured in m3/m2. The volume of mortar required for solid block is different from the volume required for hollow block.

Generally, volume of mortar required for solid block = volume of block (including mortar) – volume of block only

Gross volume of block (including mortar) = 475 x 225 x 250 = 26718750 mm3 = 0.02672 m3

Volume of block only = 450 x 225 x 225 = 22781250 mm3 = 0.02278 m3

Volume of mortar for solid block = 0.02672 – 0.02278 = 0.00394 m3

For hollow block, the hollow of the block should be subtracted from the volume of mortar for solid block to get volume of mortar for hollow block.

Table below presents the block sizes, type, joint thickness and mortar volume

Table 1; Block sizes and corresponding mortar required per block/per square meter of wall

Common construction items in Nigeria and their quantity per unit of their measurement rates - (1)

Assuming the block size specified above and the joint thickness are applicable to ones work, one can read off the mortar volume required per block from Table 1 and multiply by the total number of blocks to get the total volume of mortar required for the block work.

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Mortar usually comprise of cement, fine aggregate (sand) and coarse aggregate (stone). Having determined the mortar volume required to lay bricks or blocks, the quantity of each of these materials can be determined from Table 2 based on some nominal mix ratio for 1 m3 of mortar to enable appending of prices to them.

Table 2; Nominal mortar mix ratio and required constituent materials

Common construction items in Nigeria and their quantity per unit of their measurement rates - (2)

The same rule applicable to mortar for laying and bedding blocks applies to mortar for plastering. In the later case, one need to determine the volume of mortar (m3) required. Once the volume of mortar required is known, Table 2 can be used to get the quantity of each of the materials required within the volume. Remember when calculating these quantities to include allowance for wastes. In a follow-up article titled pre-contract allowances for wastes in Nigerian construction industry, I have shown allowances for wastes that should be made for some materials in estimation. In a later article, I would also show the allowance to be made for shrinkage because some construction materials like cement, sand, aggregate undergo shrinkage when they react with water and this shrinkage affects the volume of the plastic mass: mortar or concrete.

Civil Engineering Standards Method of Measurement (CESMM)

Concrete work

Concrete is one of the key construction materials. Concrete consists of mixture of cement, fine aggregate and coarse aggregate and it is usually measured in cubic metres (m3). To determine the quantity of concrete required for an item of work, compute the volume of that item of work by finding the product of its length, width and depth (or height). This volume is the minimum volume. Put allowance for shrinkage and waste to get the true and most probable volume of the concrete. The constituent materials can be determined by design (design mix) or if nominal mix would be used, Table 3 below shows the different constants one can use to determine the quantity of cement, sand and stone. Let me give a demonstration of how these constants are obtained using a particular mix ratio.

Assuming we want to determine the quantity of materials required to obtain 1m3 of concrete using nominal mix ratio of 1:2:4

Sum the ratio as 1+2+4 = 7 of total quantity of materials

Cement quantity = (1/7)x 1 m3 = 0.142857142 m3

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Allow 10% for waste and 35% for shrinkage, thus 0.142857142 x 1.1 x 1.35 = 0.212142857

Assuming density of cement = 1440 kg

Mass of cement = density x volume = 0.212142857 x 1440 = 305.4857143 kg

Number of 50 kg bags required = 305.4857143/50 = 6.109714286 bags, say 6.1 bags

Sand quantity = (2/7)x 1 m3 = 0.285714285 m3

Allow 10% for waste and 35% for shrinkage, thus 0.285714285 x 1.1 x 1.35 = 0.424285714 m3, say 0.424 m3

Stone quantity = (4/7) x 1 m3 = 0.571428571 m3

Allow 10% for waste and 35% for shrinkage, thus 0.571428571 x 1.1 x 1.35 = 0.848571428 m3, say 0.849 m3

Consult Table 2 below for other nominal mix ration constants. The constants below are provided for 1 m3 of concrete. Thus when you get the volume of concrete required, multiply by the values below to get an equivalent for the particular volume of concrete concerned.

Table 3; Nominal concrete mix ratio and required constituents

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Common construction items in Nigeria and their quantity per unit of their measurement rates - (3)

Reinforcement

Reinforcement is an important quantity in reinforced concrete. It is usually measured in lengths (m) or weight (kg and ton). It is the duty of the structural Engineer to provide the quantity in length of structural steel required in the building. The quantity estimator need to be in contact with the structural engineer in this aspect to get the bar bending schedule (BBS) that species this. When the total length is cumulated, allowance is also made for waste, usually 5% when the bars are cut, bent and fixed at site, otherwise allow 1% if the bars are delivered to site cut and bent. The Table 4 below provides the classes of bar available in Nigeria together with their weight per metre length and number of such lengths in 1000 kg (1 ton) of rod.

Table 4; Sizes of rods, weight per metre and quantity

Common construction items in Nigeria and their quantity per unit of their measurement rates - (4)

Reinforcement bars are tied in position using tying wires often called binding wire. The Table 5 below provides the tying wire requirement (in kg) per 1000 kg of each class of rod. In Nigeria, one roll (bundle) of binding wire weighs 20 kg.

Table 5; Tying wire requirement per 1000 kg of rod

Common construction items in Nigeria and their quantity per unit of their measurement rates - (5)

In some light construction works such as drainage or ground floor slabs that does not bear much suspended or lateral loads, British Reinforcement Company (BRC) wire mesh or welded steel wire mesh are used to provide some tensile restraint. The Table 6 below provides the fabric reinforcement to BS 4483.

Table 6; Fabric reinforcement sizes

Common construction items in Nigeria and their quantity per unit of their measurement rates - (6)

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Related

FAQs

How do you calculate quantity of construction materials? ›

To calculate the quantities of materials, you need to multiply the total centre line length with breadth and depth of the construction. The centre line length will be reduced by half of breadth of every junction where the main wall is joined with the cross walls, partitions or verandah.

What are the factors responsible for high cost of building materials in Nigeria? ›

The exchange rate of the Naira, cost of fuel and power supply, and government policies and legislations with average means of 4.37, 4.26, and 4.24, respectively, were the three topmost causes of the trend in the cost of building materials. ...

How do I calculate price per quantity? ›

The unit price is the cost per quantity of item you're receiving. The quantity might be per item or per unit of measurement, such as ounces, grams, gallons, or liters. To calculate the unit price, simply divide the cost of the product by the quantity you're receiving or check the store's shelf label.

How do you calculate quantity of bricks? ›

For a singular layer brick wall, multiply the length of the wall by the height to get the area. Multiply that area by 60 to get the number of bricks you should need, then add 10% for wastage. That's the short answer and assumes 'standard' brick and mortar sizes.

What is the most common construction material? ›

1. Concrete. Concrete is the most widely used building material in the world, making it a good starting material to get to know. However it also has significant environmental impacts, including a carbon footprint of up to 5% of worldwide emissions.

What are basic construction materials? ›

Wood, cement, aggregates, metals, bricks, concrete, clay are the most common type of building material used in construction. The choice of these are based on their cost effectiveness for building projects.

How many bags of cement and sand are in 1 cubic meter? ›

Procedure To Calculate Cement Bags In 1 Cubic Meter:

Weight of 1 bag cement = 50 kg. =0.0347 cum. = 6.25 bags.

How many bags of cement do I need for 1 cubic meter of concrete? ›

Thus, the quantity of cement required for 1 cubic meter of concrete = 0.98/0.1345 = 7.29 bags of cement. The quantities of materials for 1 m3 of concrete production can be calculated as follows: The weight of cement required = 7.29 x 50 = 364.5 kg. Weight of fine aggregate (sand) = 1.5 x 364.5 = 546.75 kg.

What are the 3 most expensive components of a building? ›

Here's the main contenders for the most expensive part of building a home and what you need to know about them.
  • The Lot. The land that your home will be built on will make up a substantial portion of the cost of the home. ...
  • The Foundation. ...
  • Framing. ...
  • Plumbing & HVAC Systems. ...
  • Windows and Doors.
5 Feb 2021

What construction materials have increased in price? ›

The price index for steel is the highest contributor to the overall cost of construction materials, itself rising 112.7 percent in the last 12 months. The price index for plastic rose 35 percent and architectural coatings rose 24.3 percent. Lumber and plywood rose 21.1 percent.

What costs the most in construction? ›

Framing is the highest material cost for most new home builds. High-quantity lumber framing averages $33,000 for a home in the U.S. This includes floors, walls and roof trusses.

How do you calculate construction cost per unit? ›

In an item rate unit price contract, each item — or unit — has a set price. The amount owed to the construction company is calculated by multiplying the rate for a unit by the number of those units used.

How do you calculate unit price and quantity? ›

The unit price can be found using a simple formula if the quantity and total cost is known. Simply divide the total price by the quantity to find the unit price. Thus, the unit price is equal to the total price divided by the quantity.

What is the formula to calculate price per unit? ›

Cost per unit formula

The cost per unit formula involves the sum of fixed and variable costs, which is then divided by the total number of units manufactured during a period of time. Here is how to find the cost per unit: Cost per unit = (Total fixed costs + Total variable costs) / Total units produced.

How much sand and cement do I need for 1000 bricks? ›

Allow 3⁄4 cubic metre of sand, 4 bags of cement and 4 bags of lime per 1,000 bricks laid with a stretcher bond.

How much is a unit of brick? ›

Depending on the type, quality, and size of brick, the price can range between $250 and $3,730 per 1,000 bricks, or $0.25 to $3.73 per brick.

How many bricks are there in one unit? ›

Now question is how many Brick in 1 CFT ?, there will be simple answer, there are 14 nos bricks in 1 CFT brick work.

What are the 7 types of construction? ›

Types Of Construction Projects
  • Residential Building Project.
  • Private Project.
  • Commercial Project.
  • Industrial Project.
  • State Construction Project.
  • Infrastructure and Heavy Construction Project.
  • Federal Construction Project.
12 Dec 2021

Which are the most commonly used materials? ›

Second only to water, concrete is the most consumed material in the world. The historic development of cements and concrete are reviewed.

How many types of materials are used in construction? ›

It commonly includes wood, concrete, steel, cement, aggregates, bricks, clay, metal, and so much more. In the olden times, people have been using pure bricks, or wood, or straw. But in this modern age, engineers have learned to mix and match the right materials to come up with higher quality structures.

What is the most common type of building construction used today? ›

Wood: Wood, obviously, is one of the most common building materials used in the world of construction, and is extremely versatile. You'll find it used for building pretty much any type of structure in any type of climate.

What is the most common construction method? ›

The Most Popular Construction Method for New Homes

According to the National Association of Home Builders (NAHB) Research Center, stick-built homes account for more than 90 percent of all new homes built in the nation each year.

What are some of the new materials that are being used in construction? ›

The most innovative construction materials
  • Transparent Wood.
  • Carbon Fiber.
  • SensiTiles.
  • Self-healing concrete.
  • Aerogel.
  • Richlite.
  • Liquid granite.
  • Bending, flexible concrete.
11 Jul 2022

What are the 9 types of material? ›

The following are common types of material.
  • Plastic. A broad category of organic compounds that are molded into a wide variety of parts, components, products and packaging. ...
  • Metals. ...
  • Wood. ...
  • Paper. ...
  • Natural Textiles. ...
  • Synthetic Textiles. ...
  • Leather. ...
  • Fibers.
24 Mar 2019

What are the 4 types of materials? ›

Materials can be classified into four main groups: metals, polymers, ceramics, and composites.

Which material is used for cheap construction? ›

Raw concrete

Being one of the cheapest building materials out there, concrete is the go-to building material of today's homes. It is a marvellous material — water & fireproof, has acoustic properties and can withstand disasters like flooring and earthquake.

How many bags of cement do I need for 1 ton of sand? ›

One may ask, “how many bags of cement to a tonne bag of sand?”, generally, there are 9 bags of 25kg cement to a tonne, or bulk or jumbo bag of sand by using a standard mix of 1:4 (1 parts cement to 4 parts sand). Thus, you will need approximately 9 bags of 25kg cement to a tonne of sand.

How many bags of cement do I need for 1 square meter? ›

Volume of Cement in Kg. =

The density of cement is 1440 kg per m. There are 0.08 cement bag is required for the plastering work of one square metre.

How many bags of sand do I need for 1 bag of cement? ›

So, One bag of cement (50 Kgs) has to be mixed with 115 kgs of Sand, 209 Kgs of aggregate and 27.5 kgs of water to produce M20 grade concrete.

What is weight of 1 bag cement and volume of 1 bag cement? ›

volume=(50 kg1440 kg/m2)=0.0345m3. Q. A cement bag contains 0.035 cubic meters of cement by volume. How many bags will one tonnes (1000 kg) of cement comprise?

How much cement do I need for 1 cube of builders mix? ›

We generally recommend a 5 to 1 ratio with cement to produce good strong concrete.

How many bags of cement make 1 metre of builders mix? ›

* 108 x 20kg bags of Boral Cement Concrete Mix will fill 1 cubic metre (m3).

How many bags of cement do I need for 1 m3 of M25 concrete? ›

So, approximately 11 bags cement are used in M25 grade of 1m3 concrete.

Which building material is most profitable? ›

The most profitable building materials in the construction...
  • Prefabricated panels. One of the most profitable materials in the construction market is prefabricated panels. ...
  • Concrete sheets or panels. ...
  • Stone cladding. ...
  • Reclaimed timber. ...
  • Industrial steel and iron. ...
  • Bamboo.
31 May 2022

What is the most expensive construction material? ›

Redwood is perhaps one of the most notable examples; however, it's also among the most expensive building materials.

What are the strongest parts of a building? ›

Structural Components
  • Foundation. The foundation is the most critical structural component of any structure and many failures are probably due to faulty foundations rather than any other cause. ...
  • Plinth. ...
  • Wall. ...
  • Shear Wall. ...
  • Column. ...
  • Floor. ...
  • Slab. ...
  • Beam.
26 Mar 2019

How much has building materials increased 2022? ›

according to the seasonally adjusted figures. This followed a 1.0% decrease in March 2022, compared to March 2021. The month-on-month change shows a 1.7% decrease in April 2022. This followed a 1.8% decrease in March 2022, on the same basis.

Why are building materials so expensive 2022? ›

2022 Notice: Material Prices Are Surging

Demand for siding and other building materials has grown over the past year. And as a result, manufacturers are increasing materials prices. Prices have gone up 5% to 10% this year, and many parts of the country are experiencing long delivery times.

What materials have gone up in price? ›

Construction materials costs are up 17.5 percent year-over-year from 2020 to 2021. The US Census Bureau says that's the largest year-over-year increase in material costs since 1970. The increase is affecting everything from lumber, to concrete, to metal and hundreds of materials in between.

What is the cheapest construction? ›

The cheapest way to build a home is to design a simple box. Sticking to a square or rectangular floor plan makes the building and design simple. Generally speaking, building up is cheaper than building a sprawling one-story home, so you may want to consider planning for a multiple-story home if you need more space.

What are the types of construction cost? ›

The four types of costs involved in a construction project are direct, indirect, fixed, and variable costs.

What are the three main components of a cost estimate? ›

In spite of the many types of cost estimates used at different stages of a project, cost estimates can best be classified into three major categories according to their functions. A construction cost estimate serves one of the three basic functions: design, bid and control.

What is material quantity calculation? ›

In material requirements planning and product costing, material quantity calculation is used to calculate the material and operation quantities that are, for example, necessary for reservations or direct cost statements. In the process order, material quantity calculation determines the order-specific quantities.

What are the formulas for construction? ›

Calculation Shuttering Area of Square column, Pile Cap, Footing etc.
...
Square
  • Perimeter or Peripheral length of Square (P) = L + L+ L + L = 4L.
  • Area of Square Cross-section = L2.
  • Area of Square (A) = Perimeter x Height of Square = 4L x H.
  • Volume of Square (V) = Area of Square (A) x Height of Square.
22 Nov 2020

How do you calculate materials per square Metre? ›

Multiply the length and width together. Once both measurements are converted into meter, multiply them together to get the measurement of the area in square meter. Use a calculator if necessary.

How do you calculate materials per ton? ›

Length in feet x Width in feet x Depth in feet (inches divided by 12). Take the total and divide by 21.6 (the amount of cubic feet in a ton). The final figure will be the estimated amount of tons required.

How do you calculate material cost per unit? ›

Cost per unit = (Electricity + Rent + Labor + Raw materials) / Number of units.

What is a quantity in construction? ›

A bill of quantities (BOQ or BQ) is usually used on larger construction projects and consists of a list of materials and services required to perform a project. The list includes materials, labor, and quantities of each, and is often prepared by the engineer or architect after project design is complete.

How do I calculate how much concrete I need for a slab? ›

For concrete, the formula for volume is as follows: length x width x thickness.
...
Here's what the math looks like for a 10' by 10' concrete patio:
  1. 10 x 10 = 100 square feet.
  2. 4 ÷ 12 = .33.
  3. 100 x .33 = 33 cubic feet.
  4. 33 x .037 = 1.22 cubic yards.
7 Sept 2022

How construction rate is calculated? ›

Cost of construction = area of plot x construction rate per sq ft. To arrive at the construction rate per square foot, you must include the following: Construction material: Cement, steel, sand, gravel, finishing, color, tiles, bricks, fittings, windows, doors, plumbing, sanitary, and electrical.

What is the 10 10 rule in construction? ›

Cost markup is not your profit. There's a rule in the construction industry known as the “10 and 10” rule. It refers to a successful bid including 10% of the total for overhead and 10% of the total for profit.

What are the types of measurements are used in construction? ›

Categories of Building Measurement
  • Gross Square Feet (GSF) = Net Usable Square Feet + Structural Square Feet. ...
  • Net Usable Square Feet (NUSF) = Assignable Square Feet + Nonassignable Square Feet. ...
  • Net Assignable Square Feet (NASF) = Sum of the 10 Major Space Use Categories of Assignable Space.

How do you calculate construction cost per square meter? ›

Approximate cost on various work of material to complete the construction for 1000 ft 2
  1. Total Cost. = Builtup area × Approx cost per sq. ft. = 1000 × 1000. = 1000000.00 Rs. ...
  2. Amount of Aggregate Required. = Builtup area × 0.608. = 1000 × 0.608. = 608.00 Ton. ...
  3. Flooring. = Builtup area × 1.3. = 1000 × 1.3. = 1300.00 Sq.

How do you calculate bags of cement per square meter? ›

Volume of Cement in Kg. =

The density of cement is 1440 kg per m. There are 0.08 cement bag is required for the plastering work of one square metre.

How do you calculate cement per ton? ›

Determine the thickness of the concrete in feet and multiply that value by 300,000 to obtain the volume in cubic feet. Multiply by 150 to obtain the weight in pounds and then divide by 2,000 to determine the number of tons.

How is load calculation calculated? ›

Calculating Load

After you know the capacity of individual circuits and of the home's full electrical service, you can then compare this with the load, which you can calculate simply by adding up the wattage ratings of all the various fixtures and appliances that will be drawing power at the same time.

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