Crack injection is the process of pumping slurry or resin into a vacuum to fill the cavities of a concrete slab. Injection work is typically carried out to aid waterproofing or to prevent corrosion of concrete structures. Because epoxy and polyurethane foams used for crack injection are two-component materials, it is critical to mix them in the correct proportions to avoid problems with unreacted polymers. They are generally considered “rigid” materials and are widely used for structural repairs by injecting cracks and voids into load-bearing reinforced concrete structures or elements.
Crack injection has arguably become the most common method for repairing foundation cracks in recent decades. However, the pillars will not seal existing cracks, which may still need to be injected to prevent leakage after the base has stabilized. Its low viscosity allows excellent penetration into cracks and strong adhesion to concrete, which helps to ensure permanent and long-lasting load transfer. Fortunately, there is an easy way to permanently repair such cracks without the need for costly and annoying digging or draining tiles.
It should be noted that the Province of Ontario Standard Specification OPSS 932 requires the use of high pressure for polyurethane crack injection at government construction sites. For filling a typical crack in a residential foundation wall, injecting at pressures above 40 psi may not be effective. This method requires a little patience, but it allows the applicator to control the injection process and ensure that the crack is completely filled. A spring-assisted dispensing tool allows complete control of injection pressures to keep them between 20 and 40 psi, the best range for complete crack filling.
They are now widely used for structural injection to seal cracks, gaps and non-moving construction joints. Crack injections are performed at low pressure (40 psi) or high pressure (typically 1200 to 3200 psi). Similarly, crack injection can work hand in hand with carbon fiber reinforcement to stabilize and reinforce the basement walls of poured foundations that have arched and cracked. Homeowners who choose to get multiple quotes are naturally confused when different basement leak repair companies propose different approaches to repairing the same foundation crack.