Geogrid with landscape fabric

Discussion in 'Hardscaping' started by Jonce, Nov 1, 2005.

  1. Jonce

    Jonce LawnSite Member
    from MN
    Messages: 34

    I have a general question about retaining walls with the use of geogrid and landscape fabric.

    With the geogrid extended from the block to the existing soil, where do you place the landscaping fabric? This may be a dumb question but I have to ask. If I wasn't planning on using the geogrid, I would put the fabric between the drainage rock and the existing soil but I don't see how you can do that with the geogrid crossing the path.

  2. Green-Pro

    Green-Pro LawnSite Bronze Member
    Messages: 1,420

    I'm certainly not in a league with most of these guys but it seems to me you could still fabric from the base level up to the first layer of geo grid, start fro first layer of grid and fabric up to second layer, etc. I would pull enough fabric up the soil face so as to "tuck" it under (away from wall towards soil) the fill at grid level.
  3. Jonce

    Jonce LawnSite Member
    from MN
    Messages: 34

    Green-Pro, that's what I was kind of thinking too. I didn't know if there was a trick of the trade that I'm missing or if that was the only option.
  4. mrusk

    mrusk LawnSite Gold Member
    Messages: 3,260

    You don't knock off the lip of the first course block before you install it?

  5. Jonce

    Jonce LawnSite Member
    from MN
    Messages: 34

    This was just a simple diagram I did in Paint, sorry I forgot that detail. The literature for Anchor Block says to knock off the lip. I'm guessing that's a standard thing to do?

    UNISCAPER LawnSite Bronze Member
    Messages: 1,426

    You wrap individual cells of fabric between each layer of grid. A 6' wide roll of fabric will wrap a 1'x2'x1' washed gravel layer and leave you a little fabric to play with. In an ideal world, you could use a 4' wide rool, but you know as well as I do that you can't create aperfect 1' wide cut when packing soil on the grid. Typically, we put the fabric in, staple the fabric to the back filled side, then sue a sheet of plywood to keep the gravel somewhat uniform, then back fill with dirt, then pull the ply wood after compaction. Place the dirt at the back edge of the grid first, then work toward the wall. That shouls pull any slack out of the grid before you compact the dirt or backfill materials

    The other thing, keep your grid horizointal at a 90° angle to the back of the wall but right at the cut line between the gravel and back fill, you can ramp it up a tad, like 2" to accomodate for any soils consolidation beyond compaction..

    Have you run any type of sheer test to determine your grid lengths yet? If you haven't I would use Strata 500, or 550, and place it all the way to the garage. Better to overbuild it then find out you have a bowing wall own the road.

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