Crack injection is a reliable and cost-effective solution for sealing foundation cracks with injections of epoxy and polyurethane. Once cured, the repaired concrete cracks will be two to three times stronger than the original concrete, providing a durable and long-lasting repair. Even if you plan to repair the crack yourself, it is wise to consult a foundation professional for advice. Although there are limitations to this method, such as not being able to apply it to multiple cracks on the same wall, or not being able to control leakage if the damage has been active for a long time, it is still a viable option.
Most foundation cracks are fine cracks that occur as concrete heals due to water evaporation in concrete; a phenomenon called plastic shrinkage. The result of the expansion makes the injection procedure more convenient for technicians: when the polyurethane expands, it fills the empty spaces and voids in the base. You may need foundation repairs if you notice external or internal cracks in walls or if doors or windows are not square and don't close properly. Both epoxy and polyurethane crack injection have been used in residential waterproofing applications since about 1980; these basement foundation crack repair methods are performed from inside the basement.
Minor cracks can cost only a few hundred dollars, but larger cracks will be more expensive to repair. There are other ways to seal cracks in block walls, but unfortunately, the best way is also the most expensive: from the outside of the base. The process includes low-pressure and high-pressure injections depending on the type of crack in concrete structures. A do-it-yourself repair kit will not seal the problem, and the crack may start to leak in the future, leading to an even more expensive professional repair.
As for weather conditions, concrete surfaces usually begin to crack within or after 12 hours after manufacturing and finishing processes. Polyurethane foam injection is ideal for filling wider cracks and cracks that may show signs of settling or movement due to seasonal changes or ground pressures. If done incorrectly, a do-it-yourself foundation repair can fail, making an exterior injection and waterproofing the only way to ensure that the crack is sealed.