Void Under Carport

Filling Void Under Carport, Annandale, Virginia


Settlement of the backfill material under a carport slab created a void. The void extended to the back edge of the slab, which allowed animals to enter the void under the carport. The open end of the void also allowed moisture to enter the void and sit against the basement wall.


Foam jacking crew sprayed high density polyurethane into the exposed area of the void to block it off from animals.  The carport concrete was constructed as a structural slab, so the void filling was to block off the entrance to the void only. Because high density polyurethane expands immediately during the installation process, the crew was able to ensure that the void entrance was completely blocked. The quick cure also ensures that animals are immediately unable to enter the void.

Foam jacking is usually done by injecting foam through holes drilled through the surface. However, in this case void filling was only to block off the entrance, so spraying from the side was possible.