Good drainage is one of the most important ways to ensure that a home you construct stays dry and free of mold. Without proper drainage systems, groundwater can collect in the basement and lead to wood rot and mold—something you don't want to deal with later down the road. HGTVpro.com shows you how to install a French drain to eliminate water problems before they arise.
French Drain Systems
The most reliable way to eliminate undesirable, freestanding water is to build a French drain system with slotted pipes, filter fabric and gravel. The outdated way to install French drain pipes doesn't require the gravel and the fabric. But without the gravel and the fabric, the French drain design can clog up with sand and soil over time.
The best way to build a French drain is to use perforated drainage pipes, which allow water to enter or exit through small openings along the pipe. The perforations can be circles or slots. But slotted pipes are better in French drain installations because they tend to reduce the amount of fine soil particles that get into the pipe.
How To Do It - Dig a trench along the outside of your footing. The trench should be at least 2 feet wide, and can be as deep as 6 feet for a basement or as shallow as 2 feet for a slab-on-grade home.
- Lay the pipe on the virgin soil. It is very important that the pipe always be sloped from a higher starting point to an ending point of lower elevation, so gravity can force the water out. The grade should always slope away from the home to ensure that the water is directed away from the walls of the home.
- Cover the pipe with at least 12 inches of washed gravel.
- Lay filter fabric over the gravel to prevent any soil from clogging the pipe.
- Back fill the foundation with topsoil back to its original grade height.
- Finally, plant your grass and you're done.
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