Foundation Drainage Flashing

Dig a trench around the entire foundation interior at least parallel to the footers. The trench should slope about a quarter inch per foot of distance moving toward a point of drainage. The footers are the lowest part of the foundation -- on average of 12 to 19 inches deep. Since many basement water issues come from saturated subsurface soil, flashing the footing drains is essential. Flashing refers to the actual metal drain that channels water down through subsurface piping.

Lay a thin layer of gravel around the trench. This is done to avoid too much sediment getting into the pipe. Heavier gravel will give the pipe a good resting place to avoid dirt sediment.

Dig the outgoing trench away from the house at those points where the slope away is steepest. If sloping is a problem, you need to dig your trenches to eventually empty out to a basement sump pump. The pump will then push the water away from the house.

Fill the pipe entrance with either a fabric or plastic filter system. This is just a set of filters that looks a bit like a screen door. They are attached to the front and end of each piece of pipe so as to eliminate any threat of sediment. This could clog the pipe later on, making the drainage system useless.

Fill the trenches with crushed stone about 8 inches above the footer height. This will secure the piping system. If you can afford it, use brass pipes. These are more durable and will not split or crush under pressure.

Measure the slope with a level as you continue to lay the pipe. This will be your only chance to lay this, so work slowly and carefully. Make sure all the pipes are securely fastened together. Ensure that your drainage pipe is at the lowest part of the slope. The point is to make a clear path of downward sloping to reach either the external drain or the sump pump.