Preparation

• A French drain can be installed to move rainwater away from a house before it can soak in around the structure's foundation. A French drain consists of drain pipe and gravel laid around a house and through the yard. Water naturally moves through the path of least resistance, and the French drain provides that path, keeping the area around the house foundation and the yard drier.
  
  The project begins with finding a low area well away from the house or a drainage ditch for the drain tile to empty into. Staking out the path for the French drain, extending from where it will empty to where it will tie into tile around the house, makes digging the trench for the drain easier.
  
  The trench around the house should be level, 6 to 12 inches wide and 1 foot below the top of the footer. The footer is the concrete poured along the ground that the foundation of the house was built on; it is the structure's bottom layer. The trench should continue along the staked line to where the drain tile will empty. The ditch for tile leading away from the house should have a downward slope of 1/8 inch per 1 foot. Then 2 to 3 inches of clean gravel need to cover the entire length of the ditch.
  
  

Installation

• Use 4-inch diameter perforated pipe for the drain tile. Pipe with holes works better than pipe with slits because the holes allow for faster water movement and do not clog as easily with small stones. The pipe goes on top of the gravel with the pipe holes facing down so that gravel and soil won't fall into the pipe. This placement also allows water to seep up into the pipe from the trench bottom and drain away quickly. The tile should be level around the house with elbows connecting the pipes for a completed circuit around the footer and a T fitting attaching the footer tile to the drain tile leading away from the house.
  
  Depending on the depth of the tile, 2 to 3 feet of round, washed gravel should cover the tile. Then 30-lb. felt paper, geo-textile fabric or 1 foot of straw goes on top of the gravel to prevent soil and silt from clogging the tile.
  
  Soil fills in the trench, with a good topsoil for the top 2 to 4 inches. After the soil is level, grass can be planted, and the trenched area will eventually blend in with the rest of the yard.