Which Waterproof Barrier Is the Best to Repair Seepage in a Foundation Wall?

15 July 2016
 Categories: Construction & Contractors, Blog

One of the biggest decisions that a homeowner may have to make is to choose which repair method is the best if water seepage is observed in a foundation wall. This article discusses two methods (sodium bentonite injections and exterior waterproofing membranes) that are commonly used to repair such a waterproofing problem. Use this information to choose the most appropriate method for the rectification of the waterproofing problem in your home.

Sodium Bentonite Injections

Waterproofing contractors can pump a slurry made from sodium bentonite clay against the external wall of a foundation where seeping has been detected. A small hole is usually dug close to the foundation wall. That hole acts as an entry point through which the slurry is pumped. The clay will then form a plastic moisture barrier after absorbing additional moisture from the soil that it contacts.

This approach has several advantages. First, it is minimally disruptive because only a small hole is dug around the foundation. Second, it is very effective for sealing small holes because the clay forms a watertight barrier around the sections of the foundation where it has been pumped.

However, the use of sodium bentonite injections has drawbacks. For instance, the clay can find its way into drain tile pipes and block them. Additionally, the clay may miss the source of a leak because the contractor cannot direct where it goes during the injection process.

Use of Exterior Waterproofing Membranes

A contractor can use an exterior waterproofing membrane, such as a membrane made from a mixture of asphalt and polyurethane, to create a moisture barrier around a foundation wall. The process involves digging a trench around the foundation wall so that the membrane can be installed against the exposed wall. The trench is then backfilled upon completion of the installation process.

This method is more reliable than the sodium bentonite injection because the contractor can be sure that the source of the seepage has been covered. The method also permits the installation of additional water control measures, such as the use of drain tiles. Those extra measures taken increase the likelihood that your home will not be affected by foundation seepage in future.

However, the method is very disruptive because it requires extensive excavation around the foundation of the house. This excavation makes the process time consuming and expensive.

Discuss these two options with a waterproofing expert. He or she will use his or her broad experience to help you to choose the most appropriate method to waterproof your foundation after assessing the specific conditions existing in your area.