How To Fix- Repair a Basement Concrete Crack
Why Concrete Cracks
Concrete shrinks as a natural process of it curing. This shrinkage causes the concrete to develop stresses and to relieve it, the basement wall cracks. This is a normal condition in a concrete foundation. Shrinkage cracks are typically less than 1/16th” in width and will eventually run the entire length of the concrete wall, from top to bottom. Common areas for a shrinkage concrete crack to develop are under a basement window, in the middle of a long wall or where the foundation “steps down.”
Once the concrete cracks it is possible for water to leak into a basement through the crack. There are several ways to repair a basement crack leak. The most effective is to perform an injection of polyurethane foam or epoxy resin into the basement crack.
Epoxy Resin Concrete Crack Repair by Injection
Epoxy concrete crack injection does not only stop water but also provides structural strength. Like the familiar epoxy glue, it fills the crack and glues the concrete. Its strength and bond with concrete greatly exceeds the strength of the concrete itself. And the high bond and tensile strengths of epoxy prevents further elongation and yawning of structural cracks. Epoxy low pressure crack injection method insures that the full depth and length of the crack is filled. It fills cracks in walls up to 24 inches thick
Polyurethane Resin Concrete Crack Repair by Injection
Polyurethane resin are injected into the basement crack in a liquid form. This allows a gentle and slow filling process of the basement crack that will completely fill the crack. After a few minutes the polyurethane will begin to react with the water in the crack to begin foaming. Water is actually the catalyst that converts the liquid polyurethane into foam. This foaming action increases the volume of the polyurethane up to 30x its liquid form.
As the polyurethane foam expands it fills the basement crack from bottom to top and front to back. The finished foam will be a closed cell flexible structure that will not allow water to leak into the basement crack. In fact, if there are any voids in the soil outside of the basement- such as under a rock or if the foundation is backfilled with gravel-the polyurethane foam will expand and extend out into the void.
The polyurethane foam forms a strong bond to the concrete. This bond will be able to withstand the hydrostatic pressure that may develop from high ground water levels. High ground water levels are typically caused by heavy rains.
Why Polyurethane or Epoxy is Better Than a Patch
No other concrete crack repair process can do what polyurethane or epoxy injection can do. Surface patching of the crack is just that. Only the inside of the basement wall is covered by a repair. Chiselling out the concrete crack and filling it with hydraulic cement only fills a portion of the crack. Water can still enter the basement crack and will eventually force out the patch or hydraulic cement and the patch will re-crack again and again allowing water to enter. Patching a crack only makes it worse for most professionals to repair it later. It will also affect the cost of the repair later by a professional.
Fast and Easy Repair
Basement concrete crack injection is a quick repair process that stops water leaks. The technician does not have to drill into the concrete to do it with epoxy, with polyurethane he has to drill holes. For this reason the basement crack repair is a clean process. The technician will attach ports to the surface of the basement crack that allow the liquid polyurethane to enter the basement wall and stop the leak.
Once the basement wall crack repair is completed, water will not be able to leak into the basement. Now the homeowner’s possessions will be safe. As will any insulation on the basement walls, the drywall or the framing used to finish the basement.