During the retaining wall building project, many DIY or beginner builders get confused with a question: How many retaining wall blocks do I need per square? The question is valid and common, as beginner builders don’t have an idea regarding the requirements of wall blocks. To know the exact number of required blocks, it is important to understand the calculation methods. Knowing calculating techniques helps to estimate the retaining wall block requirements using a simple formula. This guide explains methods to calculate the required retaining wall blocks per square meter during the construction of retaining walls.
What “Per Square” Means in Retaining Wall Construction
“Per square” in retaining wall construction means the surface area of the wall measured in square meters (m²) or any other units. It helps in calculating the block requirement to build the wall. Measuring “per square” helps in comparing block types and estimating block amounts required for a project. It is calculated by measuring the height and length of the estimated wall. Along with the calculation of wall area, it also calculates the size of blocks, as they come in different sizes. The face area of the wall is divided by the area of the block to find out the total block quantity required.
How Wall Height, Block Size, And Wall Length Affect Block Quantity
Wall height, wall length, and block size directly affect the count of retaining blocks required for the retaining wall project.
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Wall height: Wall height directly impacts the number of blocks required for the project. The higher the wall, the more blocks are required.
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Wall length: The length of wall also influences the block requirements. The additional length of the wall increases the area of wall face requiring a greater number of blocks. Similarly, lower length means fewer blocks.
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Block size: If the size of block is large, it covers more area, meaning you require less blocks for your wall. Similarly, if sizes of blocks are small, you require additional number of blocks to cover the wall.
Hence, the wall height, length, and size of block determines the quantity of blocks required for the project.
Simple Formula to Estimate Blocks Needed
You can estimate the amount of blocks required for your wall building project by using a simple formula:
Number of blocks = Wall face area ÷ Block face area
Where the wall face area is calculated by multiplying length and breadth of the wall. Meanwhile, the block face area is calculated by multiplying its length and height.
For example:
If you are building retaining wall with a length of 10 m and height of 1 m, the total area of wall will be 10×1= 10 m².
And if the size of wall block is 16 inches in length and 10 inches in height, its total area will be 1.11 square feet or 0.10 m².
Now, to calculate the total number of block requirement, you may use formula:
Number of blocks = Wall face area ÷ Block face area
=10÷0.10
= 100 blocks
And it is recommended to add 10% extra to cover damages. As the calculation estimates 100 blocks, you require adding 10% extra blocks, constituting a total requirement of 110 blocks for your project.
Why You Should Allow for Extra Blocks
When calculating the block for your retaining wall project, it is important to allocate 5 to 10% more blocks than your calculated amount. The reasons for allocating extra blocks are:
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To compensate for waste from cutting blocks at curves and corners
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To manage variation in block placement
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To recover breakage and damage of blocks during placement
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To cover changes in design
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For repair and maintenance in the future
Conclusion
The amount of retaining wall building block requirements depends upon its size and wall face area. Walls with additional height and length require higher number of blocks, while smaller walls require fewer blocks. The size of the block also matters, as smaller sizes require more blocks and large one requires few. You may use simple formulas to calculate the required number of blocks. It is important to consider 5 to 10% of extra blocks in addition to your calculated amount to compensate for waste and damage. For more information and reliable supplies related to construction and retaining wall projects, contact Austrina Steels. Austrina Steels offers high-quality construction supplies to make your project long-lasting and attractive.
