Dewatering Construction Sites: What Effect Does It Have on Below-Grade Waterproofing?

About Me
The Big Build: How to Use Heavy Construction Equipment

My name is Jerry, and I run a small construction company in Perth. My team normally completes relatively small jobs such as plastering walls, repairing electrical systems and constructing patios. However, one day a big client got in touch to say they wanted me to help them construct a large apartment building. I have never taken on such a big job before, but I thought it was a good chance to grow my business and gain some new skills. A friend who has completed large scale jobs before advised me on how I should hire the people and heavy construction equipment needed for the job. I learnt a lot from him, and my company has since completed several more big construction jobs. I have decided to start this blog to advise others how to hire and maintain heavy equipment.

Dewatering Construction Sites: What Effect Does It Have on Below-Grade Waterproofing?

13 March 2019
 Categories: , Blog

Groundwater has a huge impact on the quality of construction projects. Building and structure foundations extend deep into the ground for firm anchorage. If the ground has too much groundwater, the soil lacks the right formation needed to withstand the weight of a building. Therefore, construction specialists must dewater the site to change the composition of the soil. This will ensure the ground can support anything they want to build. The following information will broaden your understanding of the dewatering process:

Permanent versus Temporary Dewatering

You can dewater your construction site in two ways. The first option is permanent dewatering. Your builders can carry out this process using subsurface drainage, exclusion, or special dewatering pumps. The objective of permanent dewatering is to ensure that you always maintain the underground water level below a certain point so that it doesn't affect your foundation. Essentially, permanent dewatering cuts down the effects of buoyant forces and keeps the underground water from leaking into your foundation or basement. 

Secondly, you can opt for temporary dewatering. The objective is to get rid of water from the site when carrying out construction. When the project is complete, you get rid of the dewatering techniques to restore the natural water table.   

Selecting Your Form of Site Dewatering 

The primary determinant of the dewatering method you use depends on the quantity of water in the soil. A high water table means that your site has a rich supply of groundwater. The risk of flooding and seeping into your foundation is quite high. Therefore, you should consider permanent dewatering systems. Go for exclusion techniques that such as the construction of an impermeable layer between the water table and your foundation. They are very reliable.  If your site has a low water table, consider going for temporary dewatering techniques. Dewatering pumps are the best choice in this case because you can always use them when need be. They give you control over the whole process of dewatering. 

Compliance Requirements

Note that dewatering can affect the surrounding soil structure. Construction authorities have strict compliance requirements to safeguard other property owners regarding your dewatering techniques. They require you to do the dewatering in the footprint of your project rather than the outside the excavated area. The danger of doing it outside the footprint is that you will encourage settlement of the soils outside the site, which affects the structural integrity of surrounding facilities such as roads.