of Home Improvements
How to build a French Drain outside your home
It's the water
you can't see that can destroy your foundation. Pitch or tar used to waterproof
exterior walls at the time of original construction often deteriorate
in 3 to 5 years leaving the walls unprotected against the tremendous hydrostatic
pressure of a high water table, underground streams or capillarity.
Make yourself a plan
How are you going to dig your trench? You really don't want to dig it twice. Size of the trench will vary depending on your property, distance to travel, and pitch needed. Six to twelve inches wide should be plenty for most situations. Depth will be relative to your landscape and getting proper pitch. There must be enough pitch so that the water will flow in the right direction. While digging it's a good idea to keep checking to make sure you maintain the proper pitch.
Make sure that
your trench will not disturb someone else property
Getting the water to go where you wish is essential for improving yard drainage; the grade will facilitate your efforts.
Check yourself as you go.
if the trench for the French drain is to be 100' long and the grade 1%,
then by the time your trench is 50' long, it should be 6" deeper
than where you began excavating.
The Gravel Base
gravel, line the trench with landscape fabric to keep dirt out of the
I prefer to have the drainpipe connected to a drywell. The size would have to be determined by how much water you need to dispose of. A couple of cesspool rings is not uncommon. You may have to have someone install this for you. It's an additional expense but it's worth it, because it works.
French drain in the basement
A trench is dug around the perimeter of your basement next to the foundation walls the same way that the outside trench is dug. Twelve inches deep and twelve inches wide should be sufficient.
Start in 1 corner of the basement and pitch the pipe towards an opposite corner where the water will run into a sump pump pit. When water reaches a certain height in the pit it is automatically pumped out of the house.
Water pressure from a rising water table takes the path of least resistance. So it goes into the drain instead of your basement.
A small percentage
of basement water problems are the result of underground water levels.
When the water table rises above the level of the basement floor, the
water is constantly applying pressure, trying to get in.