- Go to your jurisdiction's permits department and speak to an inspector about your project. You'll need to know what materials are acceptable, size requirements and the proper slope for the drain. You may be required to obtain a building permit.
- French drains are built on the exterior of the home. This method involves excavating a U-shaped trench within 4 to 6 feet of the home. Make the trench 6 inches wide and 24 inches deep. Fill the bottom of the hole with 2 inches of gravel. Install 4-inch diameter perforated pipe with the holes pointed down. Cover the pipe with gravel. The system captures excess water and diverts it downhill and away from the house. Exit the pipe at the lowest point on the land. Clean the pipe periodically to prevent clogging.
Basement Floor Drain
- One of the purposes of basement floor drains is to transport waste water from a basement fixture, such as a toilet or laundry tub, to the main sewage system. Fixture drains can be located anywhere in the basement, but try to make the connection as close possible to the main floor drain, which is usually a 3-inch or 4-inch cast iron or PVC pipe that comes up out of the floor. Another purpose for a floor drain is to protect the space from flooding. This type of drain should be positioned at the lowest spot in the floor and covered with a grate. Finish the floor drain about 1 inch lower than the surrounding floor area.
Measure and mark the area where you will need to break out the concrete. You can use a circular saw fitted with a concrete cutting blade. Another option is to use a jackhammer or sledgehammer. Fill the bottom of the hole with two inches of sand. You will probably need to cut into the existing drain line and add a T connection. The connection allows you to connect the new drainpipe to the main drain line.
The size of the new drainpipe can be anywhere from 1 1/2- to 4-inch diameter pipe, depending on the purpose. For example, a shower may require a 11/2-inch drainpipe versus a 3-inch drainpipe for a toilet. If you are replacing the drain, you may be able to use the same type of materials as long as the items still meet local code requirements. The drain must have the proper slope for the proper drainage. In many areas, the slope is 1/8 inch per foot.
Put traps near the end of new drain lines where the lines connect to the fixtures or floor drains. The traps ensure that sewer gases will not come up through the drainpipes. Use a hose to run water through the drain line to test the system for leaks. If you are confident the drain is properly sealed, cover the pipe with sand and repair the concrete.