How to Install a Gravity Drain From a Sump Hole
A sump pump is used to evacuate water from basements or foundations when it accumulates from seepage or rain. The device pumps and diverts water away from a house to a location away from the foundation. To drain the water away from your house, you should install a gravity drain.
Install a Sump Pump
Use a jackhammer to cut into your basement floor and take out 1½ feet of the concrete from around the perimeter. Shovel a trench eight inches deep and 12 inches wide where you removed the concrete.
Dig a pit for the sump pump with the jackhammer. Cut out a circle of concrete at the end of the trench and use the shovel to dig a pit for the pump. Dig it deep enough so the top of the pump is level with the floor when you place it in the pit. Make sure you have a GFCI outlet close by to power the pump. Haul away the concrete and dirt in a wheelbarrow.
Drop a pit liner inside the pit. Connect a discharge pipe for the pump to the port in the pit liner with a 1½ in. PVC-male adapter. Screw it in place with the crescent wrench.
Insert a riser in the pipe to raise it to the top of the pit. Slather PVC cement on the riser and insert it into the male adapter to secure it in place.
Lower the sump pump into the pit liner. Attach the electric cord for the pump to the riser you just installed using electric tape. Place a check valve on the riser with the rubber couplings and hose clamps; tighten the hose clamps with a screwdriver.
Install another riser above the check valve and connect it to the discharge pipe that will drain out of your house. Apply PVC cement to the connection and place the pump lid over the riser.
Install the Gravity Drain
Dig a trench with a shovel outside the foundation of the house adjacent to the sump pump down to the footers of the foundation.
Angle the trench with a hoe and shovel so it slopes one inch for every ten feet along your foundation wall and away from your house. End the trench in an area where the water can drain without damaging any surrounding structures or onto a neighbor’s property. Lay polyethylene ground sheeting in the bottom of the trench. Install the drainpipe from the pump that goes to the outside of your house. Drill a hole from outside of the house through the foundation wall, adjacent to the pump with a power drill and 2-inch bit.
Install a 90-degree elbow pipe to the drainpipe coming through the wall from the sump pump. Secure it with a layer of PVC cement. Attach another 90-degree elbow pipe with the PVC cement, directing it away from the foundation. Cut a six foot-long pipe section with the hacksaw and attach it to the elbow pipe with the PVC cement. Place lengths of pre-drilled PVC piping over the polyethylene ground sheeting. Cut sections of piping to fit the length of your trench with the hacksaw.
Seal the joints of the pipe with PVC cement. Let the cement dry. Pour gravel on top of the PVC pipe so it is 6 inches from the top of the trench. Place another layer of polyethylene ground sheeting over the gravel. Shovel topsoil over the gravel.
Things You Will Need
- Power drill with 2 in. bit
- Crescent wrench
- Sump Pump plus piping and connections
- Pit liner for the sump pump
- Check valve
- Couplings and hose clamps
- Cement for PVC pipes
- Drain tile (perforated plastic tubing)
- Polyethylene sheets
- Floor edging
- Concrete (mixed)
- Electrical tape