Sinkhole questions??

Discussion in 'Turf Renovation' started by Raven386, Apr 16, 2006.

  1. Raven386

    Raven386 LawnSite Silver Member
    from CT
    Posts: 2,160

    Ok i just got a new client for this year, and i went to check out her yard, there's a sinkhole about id say 4 feet X 4 feet. maybe a little less, she says she has been living there for years and has never had any trees, septic, lines, nothing in her yard. the client also had someone come in a "few" years back and fill the same sinkhole but it was not as severe as it is now. it seems to be maybe 1 foot deep. but i just checked one area. what can be causing this?? its in the middle of her backyard. what can i do to fill it ?
     
  2. CutInEdge Lawn Care

    CutInEdge Lawn Care LawnSite Senior Member
    Posts: 677

    The big boys in Florida pump grout into the sinkholes.
     
  3. FIRESCOOBY

    FIRESCOOBY LawnSite Senior Member
    Posts: 981

    If I had to guess, I'd say it was from construction materials placed there when building, tree trash placed there when lot was cleared, or a large boulder was removed at some time and the fill that was placed has settled. If it's tree trash, it may not stop for a few years depending on the amount placed there.
     
  4. Raven386

    Raven386 LawnSite Silver Member
    from CT
    Posts: 2,160

    those sinholes in fl are about 100 times the size of the one i have to deal with lol. would rocks be an alternative to grout? or is there a cheaper, easier way to do it?
     
  5. Raven386

    Raven386 LawnSite Silver Member
    from CT
    Posts: 2,160

    i never thought about a large boulder. i wouldve never thought that actually lol. thank you. so what would be your suggestion ? i must say. i have learned so so so much in the 5 days ive been a member of this forum! and i must say thank you to all you veterans of the business.
     
  6. FIRESCOOBY

    FIRESCOOBY LawnSite Senior Member
    Posts: 981

    In the past I've fixed things like this.

    Either way, IMO, you need to find out what is causing this. This involves a good sharpshooter shovel and some time. Dig down at least 4-5 feet below grade. If you find evidence of tree trash...there's your answer. If no tree trash, you might be safe in assuming something was removed and the fill has settled.

    With what you said that someone has "fixed" it before leads me to believe that the settling hasn't stopped, but it's hard to tell without a compaction test.

    The only TRUE way to fix it right is to dig all the fill out and refill and pack it. For this a mini excavater would be golden.

    Whatever you do, you may want to rent a "whacker packer". Replace about a foot of fill and pack it well. Continue to do this until very slightly below grade and pack well. Then replace topsoil, seed, etc.

    You can dig the hole out and place rock such as rip-rap in there, but this creates additional problems most of the time. When filling the hole, it is nearly impossible to get dirt to completely fill every void around the rocks. This creates future settling problems.

    Probably the easiest and cheapest solutions is to place fill on top of the settled portion and reseed. Advise the customer that this may occur again, and it's hard to determine how long it will take. I've seen the same holes settle more within a week or palcing fill, to several months. Depends on rain, ground, and what's causing it.

    Good luck.
     
  7. Brianslawn

    Brianslawn LawnSite Silver Member
    Posts: 2,004

    heck, we were mowing a new development that had a sinkhole every 10 feet.... and its still being built. too easy to get licenses and too many people without them
     
  8. topsites

    topsites LawnSite Fanatic
    Posts: 21,653

    I mean I don't know what's causing the hole but I usually go grab a cubic yard or two of topsoil and fill it in - Depending on your trailer you'll need to be careful ordering and hauling dirt because the stuff is heavy (a ton a yard), my 6x12 single axle is somewhat over load with 2 cubes but she'll do it on heavy-rated radial tires but not with bias-ply. Under no circumstances would a single-axle trailer hold 3 cubic yards, no.

    One cubic yard = 3 x 3 x 3 = 27 cubic feet
    Your hole = 4 x 4 x 1 = 16 cubic feet

    I dare say one cubic yard should do it for starters but those holes have fooled me before. Either way, shovel and a barrow, then flatten it out nice with a landscaper's rake (regular rake is ok too but the garden kind with stiff tines not a leaf rake), spread 5 or 10 pounds of seed on that and rake that in, and voila.
     
  9. Raven386

    Raven386 LawnSite Silver Member
    from CT
    Posts: 2,160

    i dont even have a trailer yet. borrowing some ones that i usually work with... im waiting to see if i should buy one to suit a ride on or just get one for now. dont want to buy a trailer just to have to replace it 6 months from now. ive been haulin a yard at a time in my 2500hd. no fun at all!!!! i need a dump-body!
     
  10. Raven386

    Raven386 LawnSite Silver Member
    from CT
    Posts: 2,160

    thanks everyone!
     

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