Injection Connection – Using Urethane Injection Grout to Save the Foundation of a Historic Building
When the construction of a new condominium had compromised the structural integrity and waterproof qualities of the neighboring 120-year-old foundation wall, Scott Henson Architect was contacted to assist and monitor the experts repairing it to stabilize and prevent further damage.
This system utilized urethane grout injected throughout the foundation of the building to improve its water proofing integrity. The process of installing urethane grout requires only the one-part grout, pumps for injection, and water to activate the urethane grout. The inexpensive nature, relatively simple installation, and the long-lasting results of urethane grout often makes this method ideal for underground foundation repair, even in older buildings.
Before beginning the process of injecting the grout, the contractor prepared the foundation wall by drilling a number of 5/8” – 3/4” diameter holes in the affected foundation wall in a grid, about 1 ½ to 2 feet apart. Next, expanding injection ports were installed in approximately half of the holes to allow for grout injection. The holes with no ports allowed for the team to observe spread and expansion of the urethane grout and spillage of extraneous water.
Using pumps, urethane grout was injected into each port at a pressure of 500-1,500 PSI. The contractor added water periodically to the foundation cavity to activate the urethane grout as it was injected. They were extremely careful to apply appropriate pressure to deliver grout throughout the cavity but not too much which could damage the rubble wall.
This method of urethane injection can be used for foundation wall repairs, or in this case, waterproofing. Once activated and cured, urethane grout improved the foundation of the building not only by sealing cracks and holes to prevent water infiltration, but also adding strength to the building foundation. Even buildings over a century old can maintain structural integrity and withstand many more years of use as new construction rises around it.
Scott Henson Architect was proud to be a part of preserving and restoring this historic building for the community. If you have damage to an older or historic building, reach out to us today for a consultation. We are proud to lend our expertise in both traditional and modern building preservation techniques, approaching each case with a creative emphasis on sustainability as well as an awareness of each building’s unique and storied past.