subbase dilemma

Discussion in 'Hardscaping' started by EgansCountryGardens, Mar 11, 2008.

  1. EgansCountryGardens

    EgansCountryGardens LawnSite Member
    Posts: 163

    This is a new one to me, and I've been doing hardscapes for a while-
    We started a patio job today, excavated out the soil down to the subbase, and for some reason the soil is very wet. Now this job is on the ocean, but it is on a bluff about 100' above sea level. I don't know if it is possible for some sort of underground water spring to go up this high or not. It is just shy of the highest point in town.

    Anyway, when you step on the soil, it all moves as one till about two feet away from where you are stepping (does this make any sense)

    It rained here heavy three days ago, but I would think that it should have all leeched out by now. By the way, it is all sandy soil.

    I test dug down about 3 feet below the subbase level, and there is no standing water or anything.

    My question is, do I install the patio with a geotextile filtration fabric, then my 5" of base (I use densegrade material where we are.) Of course, then my 1" of bedding sand, and pavers.

    Will the geotextile alleive this problem?

    Anybody ever have this problem?
  2. shovelracer

    shovelracer LawnSite Silver Member
    Posts: 2,009

    Your subgrade sounds to be over saturated. You will only get full compaction, IE 98% Modified Proctor, if the moisture content is just right. It may need to dry out a little. Secondly geotex will not fix this problem, but should be placed in between your base and subgrade anyways. You will more than likely hear 2 responses. 1 - dig down till you find a suitable subgrade. 2 - pound a bunch of 3-4" stone in there until it wont take it anymore. Either way I dont think you are ready to lay your base.
  3. bigviclbi

    bigviclbi LawnSite Senior Member
    from nj
    Posts: 895

    I'm by the shore and this happens. You need to let it dry out. Adding portland cement helps as well, or digging twice the depth of the base as usual and using crushed concrete first. It will help absorb the water.
  4. EgansCountryGardens

    EgansCountryGardens LawnSite Member
    Posts: 163

    Wow. Those were quick responses. Thanks for the input guys. I think I'm just going to wait and let it dry out. Hopefully it does, they are talking rain this weekend.
  5. Captains Landscape

    Captains Landscape LawnSite Senior Member
    Posts: 333

    You have clay mixed in with all that sand as well. Don't be shocked if it takes a week to dry out, or never does, and we have more rain/snow coming all week. I know exactly what you mean, you don't have standing water in your base it just acts almost like quicksand and has a lot of air in it. That's just the clay thawing out slowly. If you want to start now, dig out all the saturated clay until you hit dry sand soil and install more base then normal. You may have a huge overdig, and it may still even be necessary after weeks of waiting for it to dry.
  6. EgansCountryGardens

    EgansCountryGardens LawnSite Member
    Posts: 163

    f**king great. Just great. Captain's whereabouts in Plymouth county are you?
  7. Captains Landscape

    Captains Landscape LawnSite Senior Member
    Posts: 333

    I'm in the "Delux" part LOL. You know where...
  8. EgansCountryGardens

    EgansCountryGardens LawnSite Member
    Posts: 163

    Roxbury?? No, the other bury. Right? I'm in Manomet. Probably see you around. We are doing the home show first week in April at the Kingston Mall. (I don't know why I'm bothering though.) I also have a Garden Center down here. I used to work at That Bloomin Place for years when I was younger. You might be familiar with that place. Thanks for the advice on the subgrade. I figured I was screwed on that anyway.
  9. vntgrcr

    vntgrcr LawnSite Senior Member
    Posts: 282

    Deluxbury!!!! Love that town! I am on the Cape and know what you are talking about. No other way but to dig out the clay mixture until you hit dry "stuff". You should hit it within a foot or so. I don't think you have a huge overdig, but get it out, put your dense grade down, compact the #$%# out of it and you should be good. They are talking showers tomorow. Are you guys seeing much work up there? Not much down here..........................
  10. Captains Landscape

    Captains Landscape LawnSite Senior Member
    Posts: 333

    I refuse to break ground until the first of April.

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