Installing French Drain

Discussion in 'Homeowner Assistance Forum' started by mblanco2000, Jun 10, 2012.

  1. mblanco2000

    mblanco2000 LawnSite Member
    Posts: 7

    I will be installing a french drain in the back yard and running it to the culvert in the front. The run is approx. 125 ft. I have a couple of questions that I wanted to try to get answered before I do the installation. I already have it trenched, but will need to finish out some of the digging manually and need to get my slope correct.

    I read this forum post on french drains that was pretty helpful, but I had some additional questions:
    http://www.lawnsite.com/showthread.php?t=253922

    What should my slope be?
    After reading the forum post I decided to line the trench with a poly landscape fabric, and I was going to use those U shaped crampons to secure it.

    I have gone to Lowes and Home Depot to look at the perforated smooth pipe. The 4" perforated pipe has holes on one side, which makes sense, but which side do you put facing down? I would think you would put your holes facing down, but I am not sure. I have searched quite a bit on this and can not get a good answer.

    Any special type of rock that I should use? Then if you guys have any other suggestions please let me know. Thanks so much.

    MB
     
  2. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    Slope down hill and holes up
     
  3. mblanco2000

    mblanco2000 LawnSite Member
    Posts: 7

    Posted via Mobile Device
    So you guys recommend putting the holes up. Do you also recommend using the smooth perforrated pipe vs. the blk corrgated pipe?
     
  4. mblanco2000

    mblanco2000 LawnSite Member
    Posts: 7

    Also do you guys recommend using washed limestone or washed river rock?
     
  5. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    I like the black perf pipe with the sock already on it. It has holes all around it too. It is too easy to get the drain boxes and such for it.

    Just buy the cheapest aggregate you can find.

    Slope is note all that important provided you have some and avoid sags.
     
  6. mblanco2000

    mblanco2000 LawnSite Member
    Posts: 7

    The only concern I had on the corrugated pipe was the ridges filling up w/ silt. I thought people really recommended using smooth pipes for a french drain.
     
  7. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    Well they do slow down the flow a little but they also create a turbulent flow. That is part of the whole point of the sock.

    There is one product that is wrapped and has some packing peanuts in it. Eliminates the need for gravel.

    There are a lot of neat products on the market these days.
     
  8. Mrsamman

    Mrsamman LawnSite Member
    Posts: 30

    Use the solid pipe. Black pipe is hard to clean out and gets crushed over time. Engineers say to put the holes on the bottom.
     
  9. Mrsamman

    Mrsamman LawnSite Member
    Posts: 30

    Washed limestone
     
  10. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Posts: 2,174

    Lots of answers. In plumbing a house for sewer: 1/8 per linear foot. For every 8 feet drop 1". Two ways to install pipe. If buried where run off is from a house without gutters then the holes face up to catch the water and carry it elsewhere. If guttering around the bottom of a house a membrane such a 6 mil plastic goes down and the holes face down to channel the run off. You could have two application in one system. If protecting a basement then the second method would work better. but then after the flow is 8-10 from the structure then the holes should go up to catch any ground water..
    Use the smooth PVC schedule 40 pipe. That corrugated stuff will colasp and cave in over time especially with a riding lawn mower. I prefer 1.5 rock but any course rock will work that is larger than holes in PVC. Depending on where you are located, a building code may dictate some of this.
     

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