Epoxy crack injection is an extremely effective and reliable crack repair method, specific to poured concrete foundations; for the structural repair of foundation cracks, to address basement leaks, and to prevent a foundation crack from ever leaking. When done properly by a trained injection technician, this type of foundation crack repair does not fail. Civil engineers commonly recommend epoxy crack injection to structurally repair cracked concrete structures, such as highway overpasses, due to epoxy's significant bond strength. While epoxy crack injections are not as versatile as polyurethane crack injections, for example, the repair of actively leaking cracks contributing to a wet basement, epoxy crack injection is nonetheless a very effective means of filling cracks in basement walls and preventing potential basement leaks. With an epoxy crack injection you accomplish several objectives at the same time: you are waterproofing your basement, you are structurally repairing your foundation crack, and you are preventing the occurence of a basement leak from the repaired crack.
An epoxy injection is performed from inside your basement, thus avoiding the need for foundation excavation. Epoxy crack injection is a low pressure (less than 450 psi) injection of epoxy through injection T-ports installed along the length of the crack in the poured concrete foundation.These ports adhere to the wall by the use of an epoxy thixotropic paste which is used as an anchoring epoxy. This epoxy paste is subsequently applied over the entire length of the crack and, in conjunction with the soil outside, serves as a barrier to confine the epoxy within the crack so that the injected epoxy is contained within the foundation wall over the entire length of the crack. The injected epoxy will cure within a matter of hours and bond the two sides of the crack back together in addition to filling the crack through the entire thickness of the foundation wall (typically 8"), thereby sealing the crack permanently because the crack essentially no longer exists. In fact, the bond strength of epoxy exceeds the strength of the concrete itself! There is no drilling involved with an epoxy injection and odors are minimal. Most customers choose epoxy injection for crack repair where they have the option between epoxy and polyurethane crack injection, due to the longer warranty offered with an epoxy injection and because it is a structural repair. An epoxy crack injection is carried out in two steps as follows:
Preparing The Crack For Epoxy Injection
During this step, the injection technician will gain access to the repair area from inside the basement. Subsequently, the injection T-ports will be installed, and the crack will be covered over with the epoxy thixotropic paste. Crack preparation for an epoxy crack injection typically takes 30 minutes.
The epoxy paste must be allowed to cure for approximately 30 - 45 minutes, depending on the temperature and relative humidity in the basement, before the second step (the actual epoxy crack injection) can begin. Failure to allow the paste to fully cure may result in an incomplete injection of the crack. It should be noted that the paste (anchoring epoxy) will not adhere well (if at all) to a damp or wet surface; consequently, the bond strength will not be optimal. Without a strong bond, the epoxy paste may not be able to withstand the injection pressure; therefore, an epoxy injection is only a viable crack repair option if the wall surface is completely dry.
Injection of the Crack with Epoxy
It is during this step that epoxy resin is injected into the crack. The time required to inject a crack varies with the width of the crack, the viscosity of the epoxy used, and generally takes 15 - 45 minutes per crack. As a result of our extensive experience in performing epoxy crack injections, AquaGuard Injection & Waterproofing® uses epoxies with differing viscosities (thickness) as dictated by the characteristics of the crack being injected; this is required in order to prevent the epoxy from bleeding through the crack into the soil on the outside during the curing process which takes several hours. The technician begins the epoxy crack injection through the lowest port until epoxy travels up the crack and becomes visible in the injection port immediately above it; then the lowest injection port is capped-off and epoxy is injected into the port immediately above it. This process is repeated until epoxy is seen exiting the crack at the top of the foundation, or until the crack has been filled up to grade.
Note: Several technical factors need to be taken into account to determine whether a basement leak should be injected using epoxy or polyurethane. Only our trained technicians can determine which injection is most suitable for any given foundation crack. As stated previously, epoxy crack injection is not as versatile as polyurethane crack injection; therefore, not all cracks can be properly injected using epoxy resin.
Tip: If you wish to test the effectiveness of an epoxy crack repair using a garden hose, you must wait at least 24 hours after the epoxy crack repair has been completed so as to not interfere with the curing of the epoxy within the crack.
