Seal RCP Pipe (Stormwater)

Seal RCP Pipe to Stop Sinkholes, Richmond, Virginia


Sinkholes repeatedly opened up along path of 48″ RCP stormwater pipe running down easement between homes. Previous efforts to repair the problem, including installing canned insulating foam and sand bags thrown down the sinkholes, were unsuccessful. The identified cause was improperly trained installation crews, who damaged pipe bells and did not properly install the butyl gaskets. Additionally, the pipe installation was done with too narrow of a trench, so there was inadequate fill below the pipe’s spring line, allowing for an easy path for water flow.

Organic matter and grass from the surface were present in the joints, indicating uninterrupted flow of water from the surface, down to and along, then through the pipe.


High density polyurethane injection through the walls of the pipe to fill voids and seal joints.


Crew placed 18.8 cubic yards of high density polyurethane grout to fill the voids which were created along the pipe, and seal the joints. The work was completed over a period of 6 hours.  No surface disturbance was necessary, and the joints were all successfully sealed.