By Adeyinka Adeboye
To accurately calculate the materials needed for building setting out, it is crucial to understand your role as a young engineer and the client’s role in the construction process.
The client’s responsibility is to provide the cost for setting out materials and pay you for proper setting out.
Many people struggle with calculating materials accurately and quoting for them. In this guide, I will show you how to calculate materials for building setting out by following the 9 steps:
1) UNDERSTAND THE BUILDING PLAN :
Begin by thoroughly reviewing the building plan and familiarize yourself with the dimensions and measurements mentioned in the plan. This will enable you to determine the accurate quantities of materials required. It is essential to be able to read and interpret working drawings to prepare setting out materials effectively.
2)IDENTIFY THE SETTING OUT MATERIALS :
Identify the different materials involved in the setting out process.
This include items such as pegs, profile boards, nails (2″ and 3″), lines, builder square or laser level, plumb, angle two-sided plumb, claw hammer, and a large hammer.
3) CALCULATE THE MEASUREMENTS:
Use the building plan or layout drawing to measure the length and breadth of the area.
Add an additional 1.5m or 1m as a setting out spread away from the excavated pit.
Calculate the length by adding 1.5 to the first and second sides, and do the same for the breadth.
For example, if the building length is 20m and the breadth is 10m, and we are using a 1.5m spread away from the foundation, the calculations would be:
Length = 2/1.5 + 20 + 1.5 = 46m
Breadth = 2/1.5 + 10 + 1.5 = 26m
Total = 46 + 26 = 72m
4) DETERMINING THE MATERIALS TO BE USED LENGTH AND SIZES :
Consult material specifications or physical market survey to ascertain the normal market size of the required materials, especially wood.
For example, the length of wood is typically 3m, and pegs usually come in bundles of 20 pieces.
Confirm these specifications locally or use commonly available data for the sizes and price.
5) CALCULATE TOTAL MATERIALS REQUIREMENTS :
FOR PEGS:
Divide the total girth of the layout by the 1.5m spread to determine the number of pegs required per one length of 3m profile.
For example, if the total girth is 72m and the spread is 1.5m:
72m / 1.5 = 48 + 1 = 49
Add the beacon pegs, typically determined by the number of points in the surveying plan (usually 4 points for regular shape ).
Add the squaring pegs for the 4 corners (usually 4 points).
Total = 49 + 4 + 4 = 57 pegs
Add 10% for breaking and damage, making it 5.7pcs.
Total now is 57 + 5.7 = 63
pcs, and one bundle is 20 pcs, so you can buy 3 bundles of pegs.
FOR PROFIL :
The length of the profile is usually 3m, but use 2.9m to account for small lapping.
72m / 2.9m = 25 pcs
Add 10% for breaking and for those that may not be strong.
Total = 25 + 2.5 = 28 pcs
One plank of 1 by 12 by 12 will give you 5 pcs.
28 / 5 = 6 planks, which cost 2,000 each, amounting to 12,000 naira.
Cutting 4 lines per one @ 100 is 4 × 6 ×100=2400
Total cost for profil is 12,000 +2, 400 =14,000 naira
FOR LINES
From past experiences, 4 lines are usually enough for a 4 to 5-bedroom bungalow or duplex.
FOR Nails
From the past experience the 2 kilo of 3 ” nail @400 =800
And
3 kilo of 2″ nails @ 400 =1200
Total =2000 naira nail for mostly 4 to 5 bedrooms bungalow or duplex.
6) BE THE ENGINEER / CONTRACTOR WITH TOOLS:
As a site engineer, supervisor, or contractor, it is expected that you have the following tools: builder square, laser level, plumb, double angle plumb, and hammer. You will charge separately for the setting out because you are providing all these tools and your expertise. My current charges for setting out range from 50,000 to 100,000 naira, but I will soon review my rates.
7) REVIEW AND REFINE :
Double-check your calculations and review them to ensure accuracy. Make any necessary adjustments or refinements based on specific project requirements or preferences. Additionally, try to gather actual cost data from the project location.
8) ACCOUNT FOR WASTAGE AND CONTINGENCY:
It is important to consider wastage and account for contingency when calculating material quantities. Depending on the nature of the materials and construction practices, an additional percentage (usually 5-10%) is added to the calculated quantities to accommodate potential wastage or unforeseen circumstances.
9) CREATE A BILL OF MATERIALS :
Compile the calculated quantities of each material into a comprehensive list known as the Bill of Materials (BOM).
The BOM serves as a reference document for procurement, costing, and construction execution. I will try to provide a sample BOM for this.
By following these steps, you can accurately calculate the materials needed for building setting out, enabling effective planning, procurement, and execution of your construction project.
The write-up is fully authored by © Engr. (Dr.) Adeyinka Adeboye
® WOli the great builder.
Feel free to share, but please give credit to the original author.
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