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portstar
french drain & storm gutter

Am installing a french drain from back of house to front street a distance of about 70 feet. Would like to pipe storm gutter downspout on back of house directly into french drain. Have not seen this done but think it should work. Does any one see a problem with this procedure. The french drain will be 3 to 4 feet from and parallel to the side of the house.

A. Spruce
Re: french drain & storm gutter

Is the house lower than the street? If not, then a French drain may not be necessary. You only need 1/8 inch per foot fall to achieve drainage, a 1/4 inch would be better, but not absolutely necessary. That equates to roughly a 9" differential at 1/8" per foot and an 18" differential for 1/4" per foot.

If you must install a French drain, then you want to keep it as far away from the foundation as possible. The purpose of a French drain is to give an underground storage area for the water to sit while it percolates into the surrounding soil. You don't want the ground near the foundation becoming unstable.

Dobbs
Re: french drain & storm gutter

portstar:

I'm not sure I understand what you're trying to do---could you specify exactly where you are having the problem with too much water---basement, downspouts, back yard, etc.---to add to the confusion there are multiple meanings for "french drain", sewer trench, etc.

One meaning of french drain is used to install 4" plastic perforated drains at the exterior base of the house foundation with a pitched drain leading to a drywell (often a ditch filled with rocks, etc.) to prevent water buildup from entering the basement.

Another meaning of "french drain" is synonymous with "drywell" (as above).

If you already have french drain tiles at the base of your foundation, then NO it is not recommended to connect storm drains from the downspouts to them--the extra volume of water often floods the basement.

If your main concern is the roof runoff thru the downspouts, then I agree with Spruce that rather than build a 70 foot trench to the street. it would be less work to build a DRYWELL/FRENCH DRAIN-type trench of 35 gallon capacity and 5' depth no less than 10' from the foundation, but preferably 15' and pitch a 4" solid drainpipe to it from the downspouts to collect & dispose of the roof runoff.

If you Google "soggy yard" drywell you will get a number of excellent sites that illustrate the different ways drywells and "french drains" can be constructed.

http://advice.thisoldhouse.com/showthread.php?t=14203
http://advice.thisoldhouse.com/showthread.php?t=5482

portstar
Re: french drain & storm gutter

thanks for your input i think the safest thing to do is install seperate line in trench for the storm gutter and drain all to the street

Timothy Miller
Re: french drain & storm gutter

Howdy, Or drain into a tree well if you have one down slope from house. Great time to plant that tree you always wanted... Be sure and put a critter resister cap on end of drain pipe so nesters do not block the pipe.

Alair
Re: french drain & storm gutter

A French drain, drain tile, perimeter drain or land drain is ditch covered with gravel or rock that redirects surface and ground water away from an area. A French drain can have hollow pipes along the bottom (see images) to quickly vent water that seeps down through the upper gravel or rock. French drains are common drainage systems, primarily used to prevent ground and surface water from penetrating or damaging building foundations. Alternatively, the French drain technique may be used to distribute water, such as that which flows from the outlet of a typical septic tank sewage treatment system. French drains are also used behind retaining walls to relieve ground water pressure.

JohnMoore4u
Re: french drain & storm gutter

You can get detailed installing/building of french drains in this article http://www.encyclopediaofhomeimprovements.com/frenchdrains.html

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