Soupy gravel?!?

Discussion in 'Hardscaping' started by Woodland, Sep 24, 2010.

  1. Woodland

    Woodland LawnSite Member
    from Maine
    Posts: 207

    I'm sure this sounds like a beginner question, but its a situation I've never encountered before. This is on a walkway I'm installing at my house (fortunately - if this is a problem). The walk is about 30' long and slopes down a hill. It is an extension of a walk I completed earlier this summer.

    I finished excavating yesterday and lined the area with Mirifi fabric. The ground here is a sandy loam that drains very well. I put in two 2" (before compaction) lifts of gravel, compacting between each and then spread another 2" lift over part of the walk before calling it quits. Last night it rained. Nothing major, 1/4" to 1/2" maybe. This morning I finished spreading the rest of the 2" lift and noticed that parts of the base were very spongy underfoot and will not compact properly if I try.

    Is this a problem with my compaction on the lower two lifts or my patience level? It has been quite awhile since I had a density test done on any of my jobs but I use the same aggregate, equipment and techniques on every job so I'm fairly confident that the compaction on yesterdays lifts is close to where it needs to be. I'm concerned that the fabric is holding water in the gravel and slowing its drainage ability and how this will effect the finished product, but I also know that using fabric (which I do on every job) is standard practices and suggested (if not demanded) by ICPI. Someone please set my mind at ease.
     
  2. zedosix

    zedosix LawnSite Silver Member
    Posts: 2,631

    Let it dry out before finishing your base. If not possible add dry portland cement to harden and soak up any excess moisture.
     
  3. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Posts: 6,412

    If the incorrect fabric is used, this could happen as fabric does have water drainage ratings.

    Although being it's just a walkway, it's my opinion that your problem is not fabric related.

    Kinda sounds like your aggregate may have alotta dirt in it?

    ,
     
  4. DeereHauler

    DeereHauler LawnSite Senior Member
    Posts: 604

    sometimes the base we get has lots of clay in it, a good dry day or 2 i think would take out the spongy feeling. I don't know what to say about future problems.
     
  5. sven1277

    sven1277 LawnSite Senior Member
    Posts: 636

    It will dry quicker if you rough it up with a steel rake a few times exposing more surface area. I have used this technique with power raking topsoil to dry it out after a hard rain.
     
  6. zedosix

    zedosix LawnSite Silver Member
    Posts: 2,631

    Typically we remove the "cowbelly" before continueing on with our work. The earth under your compacted base is saturated and either needs to be dried out with time or manually removed. Its a pita but should be done.
     
  7. Woodland

    Woodland LawnSite Member
    from Maine
    Posts: 207

    All is well. Since it was at my house, I figured I should use this as a learning experience so I removed the gravel from about 1/3 of the walk to see what the ground underneath looked like. It was damp but not soggy. Most of the moisture was in the gravel above the fabric. It seems it just takes awhile to drain through. As of yesterday, the portion that I did not remove the gravel was fine. It compacted as I am accustomed. I guess patience is not my strong suit...unfortunate, since it is raining again today so I wont be able to work on the walk after work again today. Funny how a two day project, takes two months at home.
     

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