For homeowners with poured concrete basement walls or crawl space stem walls in Olympia, Tumwater, or Centralia, rainy winter days often bring unwelcome discoveries: water trickling through a vertical foundation crack, pooling on the floor, and soaking stored belongings.
A frequent DIY reaction is to chisel a V-groove and pack it with hydraulic cement, or coat the crack with surface silicone caulk. These surface patches inevitably fail. Water exerts continuous hydrostatic pressure from the outside of the wall; surface patches merely trap water inside the crack, where it continues to dissolve concrete and blow the patch off within months.
The professional engineering solution for leaking foundation cracks is high-pressure polyurethane chemical grout injection. Polyurethane resin is a closed-cell hydrophobic polymer that is water-activated.
Our technicians drill 45-degree injection holes into the concrete every 6 to 8 inches, intersecting the interior of the crack midway through the 8-inch wall. We thread heavy-duty steel mechanical injection packers with one-way zerk check valves into the holes.
Using specialized high-pressure airless injection pumps operating at 1,500 to 2,500 PSI, we pump liquid polyurethane deep into the crack. When the resin encounters water inside the fissure, it reacts instantly, foaming and expanding up to 20 times its original volume. The foam penetrates all the way to the exterior soil, completely sealing every microscopic void with an elastomeric, permanent rubber gasket that flexes with the foundation.