French drains serve to collect and remove groundwater that would otherwise cause a problem. They’re often used along driveways, in damp areas of a lawn, and around house foundations to help keep the basement or crawlspace dry.
How far should a drain be from the house?
The downspouts need to be extended away from the home a minimum of four feet, with six feet being preferred. When downspouts are connected to underground drains, it is very important to keep all debris out of the gutters, downspouts and underground drains.
Where should a French Drain be placed?
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 two feet for a slab-on-grade home. Lay the pipe on the virgin soil.
How close should French drain be to foundation?
Recommended French Drain Installation Distance
We recommend installing the french drains between 2 and 5 feet away from the foundation. There are a few variables that impact the exact distance to dig the new drain lines to carry water away from your home.
How deep should a French drain be around a foundation?
French drain depth: About 8 inches to 2 feet deep should be sufficient for many water-diverting projects, though related systems, such as those built around foundations and sub-ground living spaces, as well as the bases of retaining walls, may be deeper.
Why do French drains fail?
Over time, a French drain may become clogged. Tiny soil and clay granules slip through the pores of the landscape fabric and gradually build up inside the pipe. Another common cause of French drain clogs is root intrusion from grass, shrubs, and trees.
Is an interior or exterior French drain better?
Both exterior and interior French drains provide effective protection against flooding and water damage in your basement. Yet, due to the costs and difficulty of installing and servicing an exterior drain on existing houses, it may be better to install interior drains.
Does French drain need an outlet?
A properly designed French drain system does not require an outlet. The water will simply soak into the soil as it flows along the perforated pipe. In fact, a French drain doesn’t require an inlet on just one end either.
How far away from house should gutters drain?
Therefore, gutters should drain properly. Gutters should drain water to at least 4-6 feet but preferably 10 feet away from the house. Ensure you connect the gutter securely to the eave of the roof. Additionally, each downspout should drain a maximum of 35 feet of gutter.
How much gravel do I need for a 50 foot French drain?
To calculate gravel needed for a 50′ french drain, multiply the length of the trench by the width and depth. If you plan to lay down 4 inches of gravel, multiply 50 feet x 4 inches = 200 cubic feet.
How deep should a perimeter drain be?
You’ll have to dig a trench around the perimeter of your footing. This trench must be at least two feet wide and six feet deep. For a slab-on-grade home, the trench can be as shallow as two feet.
What size gravel is best for French drain?
Gravel used for this layer is typically 1/2 inch to 1 inch across — the larger it is, the better the water flow and less chance of clogs and blockages. For a French drain without a perforated pipe, opt for even larger gravel, such as 1 1/2 inches across.
