In a natural way, concrete is subject to internal movements (contraction and or shrinkage), and likely to crack. In some cases, the presence of cracking is not a major problem but it is still always prudent to conduct a preventive repair. We must remain vigilant and carefully consider certain types of cracks that may prove to be a sign of a more serious problem.
A crack in a foundation can be passive or active. It is essential to determine which category or cracks we are dealing with before performing any repairs. The cracks due to the removal of concrete, poor initial compaction or premature soil filling around the foundation stabilize after the first few years of initial construction. On the other hand, the cracks caused by an upward movement caused by frost, by a slump, a soil of poor quality or poorly compacted embankment can still be active and get worse. For cracks determined to have active movement, we install reinforcement plates to strengthen and stabilize the crack and prevent possible future movement of the repaired area.
Polyurethane is a resin designed to seal leaks through foundation cracks with water infiltration. This resin, with and added accelerator mixture, reacts when in contact with water and humidity forms a microscopic seal with closed cells with excellent adhesion and long duration flexibility. It is a flexible product that allows the natural movement of concrete resulting from shrinkage and thermal expansion. Polyurethane injected into cracks expands to 20 times its initial volume, thus completely sealing the crack and sealing out water.
The injection of epoxy is a system to bound cracks with an epoxy resin. There is no expansion and it is used on dry surfaces where a strong structural repair is needed. The resin restores the original strength of concrete in the repaired area. The epoxy injected into the cracks increases structural strength. Injecting epoxy also protects the metal reinforcing bars that are situated in the walls and stops water infiltration. In short, repairing a foundation crack with epoxy provides the best repair.