Curtain wall grouting is a leak seal method that is often required when cracks cannot be identified, when walls are made of material that does not respond well to crack injection (such as masonry, stone and CMU), and when previous leak seal methods have failed.
Curtain wall grouting is the process of injecting water reactive resin behind the leaking wall in a widespread grid pattern. The water on the other side mixes with the grout and cures to a solid mass covering the surface of the wall on the other side. In addition, you don’t have water pressure dislodging external “patches” over time, as can be the case with other methods. This procedure is best done with either AP Fill 700, Spetec H100 or one of the Spetec AG100 - 300 series of acrylate grouts.
These expansive one-component polyurethane resins can be injected through the wall to cut off large flow and high pressure water leaks. The resins react with the water on the other side to form a long lasting, durable seal. AP Fill 700 has a high rate of expansion and a little flexibility. Spetec H100 has a lower rate of expansion but a bit more flexibility. The Spetec AG 100 - 300 series has a very low rate of expansion (only a slight swelling) but a lot of flexibility.