Hi, I've dug out the footings for a single story extension in the back garden and discovered a communal drainage pipe that runs across all the back gardens on the street. The building inspector has told me I don't need to move it but has asked me to dig around it and to box it off with lintels. When I asked how they weren't very clear. I'm sure this must be common but I'm not sure how to proceed, normal lintels aren't wide enough to cover the pipe (130mm). The footing are actually lower than the photos show, about level with the middle of the pipe.