Compacting sand

Discussion in 'Hardscaping' started by forestfireguy, Jul 3, 2007.

  1. forestfireguy

    forestfireguy LawnSite Senior Member
    from nj
    Posts: 601

    I was watching a crew work next door to us the other day and saw something odd so I approached the foreman to ask. They screed the sand then run the compactor over it, then install pavers in the normal way and sand as ussual.. They showed me the results after the plate running over pavers, they seemed to bed just as well as if it had been done without precompacting the sand, the reason they do this is to avoid having to be as careful with the sand, they walked right over it without leaving even a footprint. Anybody do this?????? I know this isn't ICPI approved but it seemed to make sense, I just wonder if there are any long term effects of this.
     
  2. McKeeLand

    McKeeLand LawnSite Senior Member
    Posts: 681

    this problem i see with that is that when you compact your paver into the sand it will not migrate as far between the joint, thus creating a weaker interlock.
     
  3. cgland

    cgland LawnSite Bronze Member
    Posts: 1,929

    You will tend to get more horizontal migration due to the lack of interlock.

    Chris
     
  4. ChampionLS

    ChampionLS LawnSite Bronze Member
    Posts: 1,066

    What they're doing is wasting time. When you screed sand, you leave a 1 inch (approximately) layer of sand on top of your base. I know people that are anal and think that if theres even a thumb print in the sand, the job will be messed up. NOT TRUE!. Sometimes there are jobs where you need to start in a corner and have no access. You must go across the sand. You could put a small strip of plywood over the sand and start laying that way, but a simple fact of Physics proves a inch of sand is a inch of sand. If you were to step right on the sand, and even walk back/forth many times, it's still an inch!. (as long as you dont kick it or mess it up). Also- Sand has round particles... like marbles. If the sand is compacted- either by foot or plate compactor, once you lay the pavers over it and re-tamp, the harmonic frequency will turn the sand to liquid, so it will still even out and flow up into your joints. It's a fail proof cushion. This is the reason for not using screenings. Stone dust/screenings will not "liquefy" under the vibration of the compactor and just pack down harder. This can be beneficial if your skilled at troweling or have a problem area that needs a little stiffening, but for the average job, always use concrete sand and dont tamp before. No reason for it.
     
  5. AztlanLC

    AztlanLC LawnSite Bronze Member
    Posts: 1,046

    Couple of guys I know use this method and swear by, me based on personal and ICPI instructions don't see any benefit but if it works for you why not use it, I really don't agree 100% with ICPI claiming not interlocking will be achieved if sand is pre-compacted I think is the same result if you sweep the sand from the top and make sure it gets into those joints by compacting real good, as a matter of fact I don't use sand anymore or stonedust, we use 1/4" gravel for the bedding base with real good results.
     
  6. cgland

    cgland LawnSite Bronze Member
    Posts: 1,929


    You're kidding right? Please tell me you are kidding! First, washed concrete sand has angular particles...masonry or any other improper sand has round particles. Never use a soil w/ round particles. Second, Sand NEVER liquifies when compacted....who told you this?:dizzy: The vibration settles the paver into the UNCOMPACTED sand. If your sand is precompacted it WILL NOT move into the joints and your pavers will most likely suffer from horizontal migration. Thirdly, you are saying that an inch of sand is still an inch even when you step on it. NOT TRUE! sand compacts just like any other soil. When you compact you are eliminating air molecules and pockets from the soil you are using...thus you are turning an inch of fluffy, air filled sand into 5/8" of fully compacted, airless sand. There are many more things that I could hammer you on, but I'm getting a headache from thinking about contractors like you. No wonder your jobs fail.

    Chris
     
  7. cgland

    cgland LawnSite Bronze Member
    Posts: 1,929

    You're just as bad!

    Chris
     
  8. Tim Wright

    Tim Wright LawnSite Bronze Member
    Posts: 1,034

    Hey Chris, How's it going?

    Ready for another breakfast when things slow down?

    Tim
     
  9. cgland

    cgland LawnSite Bronze Member
    Posts: 1,929

    Absolutely Tim! You name it, I'm there! BTW, things never slow down! LOL!

    Chris
     
  10. mrusk

    mrusk LawnSite Gold Member
    Posts: 3,260

    I think i am finally ready for a lawnsite get to gether. Someone needs to have a BBQ at their house!
     

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