subject: Epoxy Injection: Fixing Foundation Cracks With Hi-tech Adhesive [print this page] Epoxies have limitations for foundation crack repairs. First of all, epoxies are best-suited to repairing cracks in poured concrete walls and floors; they won't work well sealing cracks in concrete block walls, brick walls and stone foundations. An epoxy injection repair won't work effectively if preparation and application aren't done properly. For example, the dust produced by drilling injection holes can prevent the epoxy from penetrating and adhering as it should, so the installer must take care to vacuum dust from holes and cracks prior to injection.
When considering epoxy injection as a method to repair foundation cracks, it's important to first determine whether the cracks are due to shrinkage or settlement. Shrinkage cracks often occur as poured concrete cures and they're typically very narrow --just 1/16th in. wide or so (see photo). Sealing shrinkage cracks with epoxy injection helps to strengthen the wall and prevent water from entering the basement.
Modern epoxies have amazing capabilities. Originally developed in the 1930s, these two-part preparations are used to patch, repair, seal, reinforce, and protect all kinds of materials and objects. Not surprisingly, there are special epoxies designed to repair cracks in foundations. Also known as structural adhesives, these epoxies are formulated to flow into cracks and form a waterproof seal. In a typical epoxy injection repair, numerous holes are drilled along or adjacent to foundation cracks, and a special dispenser is used to mix the two components (resin and hardener) just before the adhesive is injected.
Settlement cracks are different -larger in size and often wider at the top than at the bottom. These cracks shouldn't be sealed with epoxy or any other product until the cause of the settlement is determined and corrected. Repairing a settlement crack without correcting the settlement issue wastes time and money, because the foundation is certain to continue moving, causing new cracks to form and further displacement of walls, floors and footings.
An experienced foundation repair contractor often solves settlement problems by installing piers that anchor the foundation to stable soil and then jacking displaced walls, floors and footings back into alignment. Once the foundation is stabilized, cracks can be filled and sealed using different techniques and materials, including epoxy injection and a patented crack repair technique called FlexiSpan(R). The FlexiSpan(R) system for crack repair is faster, less disruptive and more affordable than epoxy injection, so it's often the preferred choice among experienced foundation repair contractors.
