How Install a Foundation Drain Extension

Identify the location to which you want to extend the drain pipes. Look for a dry area of the yard or the most direct route to a street gutter. Mark the course by laying a rope on the ground from the current outlet to the new one. Measure the distance of the extension with a tape measure to determine how many fittings and lengths of pipe you’ll need.

Dig out a 10 inch wide and 18 inch deep trench beside the rope outline using a shovel and trenching hoe. Start at the end of the trench near the old outlet and dig down 1/8 inch further with each foot of length so any water in the system will continue to flow towards the new outlet.

Lay down synthetic water filtration fabric over the length of the trench and cover it with a 4 inch layer of 1/2- to 1 inch gravel.

Wipe the end of the existing outlet with a wire brush to remove any debris. Use a paint brush to spread primer and PVC cement over the end of the pipe and the inside of a pipe coupling. Attach the coupling to the pipe and turn it slightly to spread the cement.

Coat the open end of the coupling and one end of a 90 degree elbow fitting with the primer and cement. Attach the fitting and twist it so the curve ends in the direction of the new drain outlet.

Attach perforated PVC drain pipe to the open end of the elbow fitting with the primer and cement.

Use tee connectors to join straight lengths of the perforated PVC pipe. Turn the open stems upward and attach a drain grid over top.

Cover the pipes with a 6 inch layer of gravel to prevent debris and sediment from seeping down.

Fill in the rest of the trench with soil and re-plant the patches of grass you removed when digging the trench.