What Is the Meaning of Drain Tile in Architecture?

History

• The French drainage system is credited to an American lawyer and judge, Assistant U.S. Treasury Secretary and farmer, Henry Flagg French, who used clay pipe drain tiles to rid his Massachusetts farmland of excess water. He wrote a book explaining this method, “Farm Drainage,” in 1859, principles of which are still used today. These long clay tiles were set in an trench 1/8 to 1/2 inch apart. The gaps between the pipes allowed them to collect and drain excess water.

French Drains

• Today, contractors use perforated PVC piping connected together as the “drain tiles.” After foundation walls have been constructed, and before the area is backfilled, a gravel bed is laid in a 1-foot-wide dig trench around the exterior of the foundation, leading away from the foundation at the lowest point. Contractors place the perforated piping on the gravel bed. A filtering cloth to prevent pipe-clogging debris goes over the top of the perforated piping. The trench is backfilled with gravel and covered with dirt.

Interior Drainage Systems

• Most interior drainage systems are installed after the fact. The basement is the logical choice, where a section of concrete is removed to create a trench from one end of the basement to the outside edge of the foundation. Washed gravel covers the perforated piping, and waterproofing agents help to direct water away from foundation walls into the piping system. After installation, the concrete is replaced.

Exterior Drainage Systems

• Exterior drain systems cost more when installed after the house is built, as this method requires digging all around the foundation to remove the dirt to get at the footings. The best drain tile system is one installed at the base of the foundation during construction. After removing the dirt, the drainage system is installed like the French drain system. For homes that have acreage, the drainage system can be led downhill, away from the home, which eliminates the need for a sump pump. For homes built on small lots, however, a sump pump is required to get rid of the excess water.