How much gravel per linear foot for 4" perforated drain system with sock

Discussion in 'Landscape Maintenance' started by guitarman2420, Apr 18, 2011.

  1. guitarman2420

    guitarman2420 LawnSite Senior Member
    Male, from Midlothian, VA
    Messages: 617

    I am installing @ 3-4 lines that vary from @ 35 feet to 100 feet. I am using the perforated 4" drain tile with a sock and plan on digging a 6" trench with a ditch witch.

    1. Do I have to install gravel with the sock? I've heard that it isn't necessary-I think it is.

    2. How much gravel per linear foot?

    IRRITECH LawnSite Senior Member
    Messages: 999

    Volume measurement. LxWxH.
  3. Get Some...

    Get Some... LawnSite Senior Member
    from Kansas
    Messages: 651

    There will no be much room for hoe with a 12" bucket would leave room for a proper bed of gravel.
    A sock will get clogged fast with no gravel around it.....for french drain's the perforated lightweight 4" PVC work's well, in a good bed of clean gravel.
    French drain's can work if installed correctly.....
    But a proper grade with a good stand of turf on top is the best way to shed water.
  4. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    I have used this product from the Keeling Co. that is fabricated for this purpose. It is a perforated 4" pipe with the sock around the perimeter. Inside the sock is packing peanuts that makes the pipe 6-8 inches around. This will take up the space needed for rock filling toward the sides and bottom. Their will only be rock placed on the top of the piping depending on how much deeper you need to allow for grade changes. This stuff is really great for in bed drains and oversized gutter french draining. I am sorry for not remembering the name of the product as my supplier's site is down under construction.
    To answer your second question........the sock will succumb to mud and will not provide as much drainage as you desire. For me......I use 3/4 minus 2 chat for such projects.
  5. bigkid

    bigkid LawnSite Member
    from Gap pa
    Messages: 48

    my method of installing any sort of french drain is viewed as overkill by some but i like to know that it will never fail. What i do is dig my trench with my 12" bucket. Then i use 6' wide landscape fabric to line the trench bottom and sides and i use landscape staples to hold the excess in place till later. I then put a layer of 2b clean in the trench, then the perforated pipe and then more 2b clean to cover the pipe. I usually shoot for about 2-3" both under and above the pipe. I use the excess fabric to then cover the top of the stone and then add a little more stone to hold the fabric in place. Then i backfill and seed. The reason i go to this extreme is because at the end your whole trence essentially becomes one big drain rather than just relying on th 4" perforated pipe. If the pipe would ever happen to collapse or become clogged the drainage system will still work. Again some view this as overkill, but to others it's the best way to do it. Depends on who you talk to i guess but i have never had a call back so it's the method i swear by.
  6. Earth_Effects

    Earth_Effects LawnSite Member
    from NY
    Messages: 21

    I totally agree with this method. I've done many and the last thing you want is to go cheap and not deep enough. The things I would do differently is add more drainage stone and wrap it tight like a burrito in the trench. And topdress it with maybe 3-4" of topsoil and seed. The other thing I do especially if you're on a slope is add a "dry well" at the end of each downhill run. This give the water a place to go if downhill and won't make the turf at the end of the run to stay soggy. I just dig out 3' x 3' hole. Run the pipe to the middle. Wrap the dug out hole with fabric (not the plastic crap. Use commercial grade fabric). Backfill it drainage stone, piece of fabric on top. Some soil and seed. Done. The pipe sock is ok. I wouldn't use the black corrugated perforated pipe though. It will collapse over time. Get the 4" white PVC with the holes facing down. Use the couplers and pipe cement to add sections. Cap off the uphill end of pipe. Drills holes in the cap of the downhill end to allow water into the dry well.
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  7. Earth_Effects

    Earth_Effects LawnSite Member
    from NY
    Messages: 21

    2. How much gravel per linear foot?[/QUOTE]

    There are many calculators online to find out how much you need. Try this one
    Posted via Mobile Device
  8. bigkid

    bigkid LawnSite Member
    from Gap pa
    Messages: 48

    sounds like me and earth effects are on the same page. As he stated you can't stress enough how important wrapping the whole thing tightly in commercial grade landscape fabric is and then you can skip the sock. He also pointed out something i forgot to mention which was stay away from black perf pipe and go with sch 40 pvc. I have also used his idea of the dry well but i have done it a little different. I buy those blue plastic 50 gallon drums and dig a hole and put them in the ground. I use a hole saw and drill 1" holes in the bottom and up the sides about half way. I line the hole with fabric and stone on the bottom. Install drum and add stone around it. Again this is only done in extreme cases. If you wanna take it a step further you can put a piece of pipe coming out the top of the drum and on top of that add a pop up drain that will sit flush with the ground. If the drum gets full of water the pop up drain will allow overflow to flow out onto the ground. Just make sure if you do this that the natural slope of the ground is gona take the water away from the house. As for how much stone it depends on how you are buying it. Some suppliers sell it by the ton, some sell it by the yard so make sure you ask this when ordering.
  9. Stillwater

    Stillwater LawnSite Platinum Member
    Messages: 4,889

    wrap without gaps with a high quality landscape fabric, save the socks for your feet.

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