French Drain Estimating???

Discussion in 'Landscape Architecture and Design' started by sclk0907, Apr 23, 2007.

  1. sclk0907

    sclk0907 LawnSite Member
    Messages: 23

    How do you estimate a french drain? I have a customer that needs one installed and I don't know what to charge. How do you figure your materials if you have never put one in before?
  2. mverick

    mverick LawnSite Senior Member
    Messages: 307

    Depends on size and depth.

    Had a company here quote $5000 7 years ago for the front of a home. I just did one across the front of a home for $10,000.

    Depth ranged from 5 feet to 9 feet and 16in trench. 20 ton of 3/4 clean. It was 70 feet long with a 30foot dig to drain down a hill.

    Now comes the bigger job of landscaping the front yard after I destroyed it with the excavator and bobcat. That should be another $18,000.
  3. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Messages: 793

    If you dig this by hand
    16-23 dollars a ft includes materials --stone---4"corr.pipe and labor
  4. Mike33

    Mike33 LawnSite Bronze Member
    Messages: 1,649

    They can get more expensive than you think but i have never done 1 for 10k yet. First you need to know how long and deep. If its across average back yard let say 40' long 2 ' deep catching surface water now.
    Excavate: 2 hours
    Load and haul away dirt 2.5 hours
    Pref. 4" pipe
    8 ton 57's
    Install pipe and stone 2.5 hours
    Clean up and repair damage areas 3 hours
    Seed and mulch damage area
    This is my average formula you figure your rates for labor and stone in your area.
  5. OP

    sclk0907 LawnSite Member
    Messages: 23

    Do any of you use the landscape fabric?
    I may be wrong but i've read to put down landscape fabric, then coarse rock, pipe, more coarse rock, then small rock, cover with the remaining fabric and put down sand and seed.
    Does this seem about right?
  6. Mike33

    Mike33 LawnSite Bronze Member
    Messages: 1,649

    I do when i put a thin layer ot topsoil over stone and seed. I dont like putting soil over the stone due to it restricts the water from going in
  7. tjsquickcuts

    tjsquickcuts LawnSite Senior Member
    from Atlanta
    Messages: 942

    I had a few lawns with drainage problems, and did a pretty quick fix that helped them dry right up. I cut up the sod, excavated about 18inches, placed drainage rocks in my trench, filled over the top with sand, then a little top soil, and placed the sod back down. Was early last year, and havent had any problems since. Not sure if you are having the same problem, but I needed a fix because I laid the sod, but the builder did the grading and builders will be builders, and he wanted the cheapest fix he could get.
  8. Scenic Shrubs

    Scenic Shrubs LawnSite Member
    Messages: 8

    Depends how wet of an area/ what type of soil etc. They do make a "sock" (like fabric) that will slip right over the 4" pipe. Works pretty well. If the area is real wet. Dig the trench, lay geofabric or landscape fabric down the side bottom and up the other side. Place some rock on the bottom, lay the pipe, fill with stone. Lastly cover the stone with more fabric top dress with loam /seed. This is the most effective way to remove/ collect large amounts of water.
  9. mdvaden

    mdvaden LawnSite Bronze Member
    Messages: 1,963

    This may be the first post in which I've ever answered by saying that if you are asking this question about a simple drain line, you should go to the supplier, see the parts in person, and make your own diagram and parts list.

    Without complications, is may be among the most streamlined of procedures.

    This is one that you should be figuring out yourself.

    Formulas don't work, because we don't know how hard, wet or soft the soil is, whether you need to haul it or build a mound with it, or how much rock costs there.

    Let me give an example to explain....

    I never did a paver project - ever - in 25 years, until two months ago.

    It was a 300 sq. ft. area. So, I didn't ask anybody on here how to bid it. WHY?

    Because I need to measure the area. I need to find out the size of block, how much it covers, how much the delivery fee is, how much the tractor cost, how much the gravel was.

    No formula needed. And no need to ask anybody. Because I have to make my own materials list and price-out each item.
  10. forestfireguy

    forestfireguy LawnSite Senior Member
    from nj
    Messages: 600

    We call these "curtain drains" and after the big noreaster a couple weeks ago demand for this kind of work has gone through the roof. We typically trench anywhere from 2 feet for a slab home to 8 or 9 feet for home with a basement. We line all trenches with fabric, then lay pipe. We also tie all of the downspouts from the gutters into this pipe. Water will follow the path of leastesistance and thus when ground water, or surface water hits the "curtain" (free draining 3/4 clean or larger stone) it drops to the pipe and flows where we want it to. The fabric is essential to the useful life of this type of drain, in certain soil types soil work its way into the stone and clog it, (same principle behind stone and fabric behind an SRW)we have removed old drains with out fabric lining to find them completely clogged with soil. We have seen this most in areas with a lot of shale, which around here is almost always mixed with very poor draining soil. Anyway for the cost fabric is worth its weight in gold.

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