Grading Land to Drain Water Away from Basement

[DaileyJohn.20.decij]

I have a small house where there is a small slope from the back corners of the house to the street in front of the house. Prior to my ownership, the gutters were not properly installed and there were some depressions at the foundation of the house that attracted water. (The depressions have been filled). I have been told on numerous occasions that 95% of basement leakage problems is attributable to poor drainage and I want to fix the problems.

I would estimate that it is about 120 feet from the back of the house to the street and that the street is about 10 inches lower than the back of the house. There are small bumps (maybe several inches high) that interrupt the waterflow from both sides of the house from the back to the front. Because the slope is so gradual and because of the bumps, I know that some water will pool at some points near the house. (I just bought it a month ago, and there has not yet been a heavy rain, so I don't totally understand the drainage flow yet. I have run a hose however to get some idea of drainage flows.) If I were to place pipes on both sides of the house and underground, I believe that they would end up beneath the street level. If I tried to level out the surface and get rid of the bumps, I would be afraid that such subtle work would be difficult to accomplish. I am wondering what members of this group would suggest as the best methods to drain the water away from the house.

Thanks,

JD

[DanG]

It is too bad code is ignored so often. Code indicates a minimum of 6" of fall away from the building in the first 10'. I can show you more places that don't comply than I can ever show you that do. Developers and builders usually are not going to go beyond minimums and often don't meet the minimums.

Perhaps you can raise the grade along the building face. Do not go above weep holes in brick. Do not cover or touch any type of siding. Perhaps you can pave a sidewalk on each side to maintain a permanent drainage swale. Water moves quite well on hard surfaces with minimal pitch

A piped system can move lots of water without the cyclical problem of silting in the way surface drainage can. A level pipe can still move lots of water, though graded pipe is more normal. Pipe pitch can be quite minimal.

I have one situation where I ran 18" arch top pipe level for 200'. I established a catch box inlet at the origination of the pipe. This pipe takes on all the drainage of over 1/2 a city block. I had to create a decorative berm to cover about the last 20 feet of pipe and it terminates in a headwall disguised with a rock garden. The grass over the pipe is very hard to keep green as pipe must get much hotter than the surrounding soil and does not hold residual moisture.

This may give you a few ideas. ______________________________ Keep the whole world singing . . . . DanG (remove the sevens) [e-mail]

[CWatters]

The street might only be 10" lower but how deep is the pipe under the street and are you allowed to connect a surface water drainage system into it?

Create a decent fall away from the house for say 20" to a surface drain. Run that surface drain either to the pipe in the street or to a soakaway as far from the house as possible. This might mean rain falling say 30 feet away from the house initially flows towards the house on the surface, then into the drain and back away to the street/soakaway.

My plot slopes up at the back slightly. The patio will be graded by cutting into the slope so water flows away from the house. At the edge of the patio a surface drain collects the water from the patio and routes it around the house and then down the slope. I'm using this sort of thing and will put clean decorative stones on top to hide the metal grid...

Lots of ideas on this great site.. Check "Drainage" in the site index. It's a UK site so some terms may be UK specific. The principles work anywhere..