22/06/2026
DON'T CRAM CONSTRUCTION. UNDERSTAND THE PRINCIPLES BEHIND IT
Most times, when I crop a portion of a construction picture to explain a concept, I am not necessarily saying that what the person is doing is wrong. I simply use the image as a teaching tool to illustrate a point and help people understand the principle involved.
For example, during foundation construction, if the height of your foundation wall rises more than 4 to 5 blocks above the natural ground level, not from the bottom of the excavation trenches, you may need a tie beam or a double wall arrangement. However, this requirement is usually for the external walls only.
Many people hear "use a double wall" and apply it everywhere without understanding the reason behind it.
The external wall carries earth pressure from only one side during filling operations. Because of this unbalanced pressure, a double wall or tie beam may be necessary to improve stability.
Internal walls are different. When filling is carried out, the pressure is balanced because filling occurs on both sides of the wall. Even if you have six courses of blocks internally, the forces tend to counteract each other, reducing the risk of the wall being pushed over.
Unless your internal wall is serving as an expansion joint wall, there is usually no need to consider a double wall internally.
To understand this better, read about active and passive earth pressure on retaining walls. Also study equilibrium and force balance in structures. These concepts will help you understand why some details are necessary and why others may be an unnecessary cost.
Construction is not about cramming rules. It is about understanding the engineering principles behind every detail.
Know why you are doing something, not just what to do. That is how you will understand the different ways to achieve the right result.
Let us do the right thing for the right purpose and remain economical with our construction procedures.
