Estimating Reinforcements for a Concrete Hollow Block (CHB) Wall
There are many ways to estimate the quantity of reinforcements for a CHB Wall: by area method, by direct counting and by unit block. The easiest method and the one we will be discussing in this article is the area method.
HOW TO CALCULATE FOR QUANTITY OF STEEL BARS FOR A CHB WALL:
- Determine the area of the wall:
- Determine the specified vertical and horizontal reinforcement spacing:
- Get total required length of vertical and horizontal steel bars:
- Get the total length of steel bars needed:
- Determine the quantity of steel bars needed to be ordered:
Determine the area of your wall. The formula for a square wall is Length * Height.
Make sure to take into consideration the often overlooked information that will affect the area of your wall – for example, the depth of your beam or the underground foundation CHB.

You may get the specified spacings from the construction drawings or from your engineer. However, if you need an idea about the minimum and maximum spacings that can be used, you may refer to this table:

Based on the specified horizontal and vertical spacing, multiply your area with the corresponding values from the table to get the total required length of vertical and horizontal steel bars total required length of vertical and horizontal steel bars

Add the vertical steel bar length and the horizontal steel bar length.
Determine the commercial length of the steel bar to be ordered and divide it with the total steel bar length to get the quantity of steel bars needed to be ordered.
SAMPLE PROBLEM
Compute for the quantity of 6 meter long steel bars needed for a wall that is 3 meters high and 5 meters with the following given specification:
- Determine the area of the wall:
- Determine the specified vertical and horizontal reinforcement spacing:
- Get total required length of vertical and horizontal steel bars:
- Get the total length of steel bars needed:
- Determine the quantity of steel bars needed to be ordered:
= 5m * 3m
= 15m2

= 15m * 1.60m
= 24m2
= 15m * 2.15m
= 32.25m2
= 24m2 + 32.25m2
= 56.25m2
= 56.252 / 6m
= 9.375 ~ 10 pcs. of 6 meter long steel bars
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