The most common cause of basement water seepage in poured concrete foundations is a vertical crack. While repairing cracks from the exterior was the original remedy, the most common repair method today is filling and sealing the crack from the inside, commonly referred to as crack injection.
In a recent blog we compared two different materials used in the injection process, epoxy and urethane. I’m not going to restate that comparison, but am here to tell you how and why injecting epoxy resin into foundation cracks just doesn’t work as well as using urethane. As a basement waterproofing professional who has had experience with both materials, I want our customers to understand the problems that may arise from the use of epoxy.
So, let’s examine why epoxy is no longer the preferred repair for foundation cracks:
Epoxy, as you may know, consists of two parts, a resin and a hardener. The epoxy mixture is a liquid, which contributes to several of the problems when using it to fill foundation cracks.
Epoxy can remain in a liquid state for several hours before it hardens.
Liquid epoxy can actually run out of the crack to the outside and leach into the surrounding soil. This leaves voids in the repair that can allow water to seep in, especially at the top of the crack because gravity causes the liquid to settle.
Previously repaired cracks can be very challenging to re-seal effectively with epoxy.
If the crack has been previously injected and the original epoxy has cracked, it can be next to impossible to find the exact spot to re-inject and because the rest of the repair is a solid mass, the epoxy cannot flow to find the cracks.
Epoxy can be used only in cracks that are completely dry.
Epoxy does not bond well with wet concrete, forcing homeowners to wait until their leaks have dried up before they can be fixed. If epoxy is injected while the crack is leaking, the water seepage may actually create channels through the epoxy, creating leaks in the new repair.
Epoxy forms a rigid seal in an injected foundation crack that is prone to re-cracking.
Epoxy will crack if there is subsequent shifting or movement of the foundation and basement waterproofing companies who use it that way will not warranty epoxy alone as a structural repair. However, epoxy can be an effective crack repair if it is accompanied by structural repairs to the foundation, such as piers or beams, which stabilize the foundation against further movement.
Some basement waterproofing companies still use epoxy exclusively to fill foundation cracks and I really don’t understand why. Like any industry in the 21st Century, basement waterproofing has benefitted from technological advances and a modern basement waterproofing company uses them to benefit its customers.
At U.S. Waterproofing, we repair thousands of foundation cracks every year, adding to our total of over 300,000 homes with dry basements since we started out in 1957. We’d be happy to explain the best way to repair cracks in your foundation and our advice is free, so get in touch!