How to Replace a Sewer Pipe Next to a Driveway

Shut off the water supply to the home and instruct residents not to flush any toilets or allow water to drain out of a sink or tub.

Call the underground utility location service to identify whether underground utilities such as electrical lines exist in your digging perimeter. In most states, the number to dial to reach the locator service is 811.

Hire an experienced backhoe operator to quickly, expertly remove the bulk of the soil above the sewer line. If utility lines lie in the path of the sewer line, use a shovel to carefully dig around the pipes or cables.

Remove the old sewer line fitting from the sewer pipe where it exits the house and install a new 4-inch PVC elbow sweep. If the old sewer line is in your way, remove it. This might require breaking a clay or cast iron pipe and taking in out in pieces.

Run the new 4-inch sewer line, allowing for a fall of 1/4 inch for every linear foot of pipe. Sewer pipes work on a "gravity flow" system. Too little slope and the waste contents won't drain to the city’s main line. Too much slope and the gray water could outrun the solid waste, leaving the solid waste sitting in the line.

Connect sections of 4-inch sewer pipe, using 4-inch couplings; or install bell pipes if allowed by local code. A bell pipe has a flared opening at one end; the fleet or unflared end of one pipe fits snugly into the flared end of the next pipe. When attaching PVC couplings or other fittings, use PVC cleaner and PVC glue on every fitting as directed by the products’ manufacturer.

Tie into the municipal sewer main. It’s unlikely that your local building authority will allow you to perform this task unless you are a licensed plumber. Building code has the final say, but the standard method of tying into a municipal line involves installing a saddle fitting on top of the line and attaching the end of your sewer line to a 4-inch stub on the top. This allows your line to drop into the municipal sewer line, instead of connecting horizontally.

Fill around the new pipe with fill sand and cover the surface of the pipe with 6 to 12 inches of sand to reduce pipe movement.

Backfill in “lifts,” which involves spreading 6 to 12 inches of soil in the trench and using a plate compactor to compress it before adding another 6 to 12 inches and doing the same thing. Not all sewer trenches are backfilled in lifts, but if the trench runs alongside a driveway, compaction is necessary to prevent destabilization of the soil beneath the driveway.