Subgrade moist in spots - O.K to install fabric and base?

Discussion in 'Landscape Architecture and Design' started by turfquip, Sep 4, 2000.

  1. turfquip

    turfquip LawnSite Senior Member
    Messages: 860

    Hi everyone:

    I'm doing a driveway parking area with pavers. My hole is ready except for a few wet spots where a recent rain leaked through my protective plastic covering.

    I have typar spunbond fabric on hand and ready to install, and my question is, as the title of this thread implies...can I go ahead and install fabric and base today or should I wait until subgrade dries out completely? The subgrade is not completely wet, just in a few areas.

    My customer is getting impatient; I have a compactor rented and sitting idle; it could rain again; etc, etc,

    Help!~ What should I do?
  2. paul

    paul Lawnsite Addict
    Messages: 1,625

    Start the job, moisture will help compact the base just make sure your deep enough with your base. Your fabric is not the best for what your are doing, a woven fabric is better unless you are using a heavy fabric(6 oz or up). Make sure your subgrade is compacted and you have at least 8" of base down, compacted in 2" lifts. what type of edge restraint system are you using? Don't want any more problems like the last post:)

  3. turfquip

    turfquip LawnSite Senior Member
    Messages: 860


    Thanks, I was hoping to hear from you or one of the other resident paver experts.

    About the fabric....what is the problem with this type? I read the specs on it and it seemed to offer the benefits I am seeking....

    I will be using snap edge (sp?)

    Also: How can I run a compactor over the subgrade with wet spots? Will it make a muddy mess?

  4. paul

    paul Lawnsite Addict
    Messages: 1,625

    I use a spun fabric but unless it's a heavy fabric you could have problems with rupture. tear strength and puncture strength are most important for a parking area, turning of the tires will cause forces to try to move pavers. check with your supplier on the strenght of the fabric (look for 300 lbs puncture)
    as for the wet spot just throw some gravel down (about 1") then run your compactor over it.
  5. turfquip

    turfquip LawnSite Senior Member
    Messages: 860

    O.K., now you've got me wondering about fabric. The specs say that this material will help "squeeze out" excess moixture that may be present. If fabric disallows moisture from reaching base....still O.K. to begin job? Will present moisture still assist in compaction?

    Better off skipping fabric all together??


    [Edited by turfquip dot com on 09-05-2000 at 12:50 PM]
  6. paul

    paul Lawnsite Addict
    Messages: 1,625

    No fabric will take out moisture, all fabric is for is support for poor subase, or very heavy loads, fabric is not needed for most jobs, go here to find more info on paver installation,

    or e-mail me for more info @

    also could go to lawnsite chat and find me
  7. turfquip

    turfquip LawnSite Senior Member
    Messages: 860

    Paul, How much water should be added (if any) to each 2" lift to facilitate compaction and/or ****** dust?

    Also, how many times should I run the plate over each lift.....and is there a recommended pattern which is more efficient....or does a more thorough job.

    I started that job today and opted NOT to use fabric at all since more than one reference source did not recommend it. I first filled the pock marks in the subgrade with 1 to 2 inches, compacted twice over, added 2" - 3" more compacted again twice over in a circular pattern. We used nearly 8 tons of material today and I've got another nine tons of 610 mix on the way tomorrow(first out) for the next lift or two. The plastic is back on for the night.

    Thanks for you help and suggestions. Are there any pitfalls to watch for at this point?

    Highest Regards,

  8. paul

    paul Lawnsite Addict
    Messages: 1,625

    optimum moisture is 10%-15% for best compaction most stone from the quarry carries this so if it fresh out of the quarry you should be ok, Their is no real way of telling how much compaction you are getting unless you have a nuclear compation tester (ok guys even I don't have one of these) just run the plate compactor over it 3 or four times and if after the last past your not moving any gravel down your looking good, one test i use is a 10" spike that we use for paver restrant, if its hard to pound in you good if it goes in easy then compact some more.

    Ok next you need to make sure your grades are right for your final lift use a pipe 3/4" id black iron is best(don't use thin wall bends too easy) and roll over your base checking for low spots or high spots, go both ways. fix these and you should be ready to install sand and pavers.
  9. Stonehenge

    Stonehenge LawnSite Bronze Member
    from Midwest
    Messages: 1,276

    I don't know if the pattern of compaction makes any difference, but I usually go in a different direction each time - first and second time perpendicular to eachother, next two same, but skewed 45 degrees from first two, then back to original pattern (and I usually make extra passes wherever the pavement ends - grass, other pavements, etc).

    Good luck on the project!
  10. turfquip

    turfquip LawnSite Senior Member
    Messages: 860

    Thank you Stonehenge. I took you advice and compacted in three directions. After applying Paul's spike test I would categorize the base resistance as "moderate". Maybe I need to hit it again....I'm using a 3000 psi machine.

    A couple more observations: There seems to be an uneven distribution of 'fines' on the top surface of the first lift...any cause for concern? In other words, areas where fines are not noticable on top. Spike resistance seems equal in these areas as well as 'powdered' areas BUT the compactor keeps leaving a rooster tail of loose gravel on each turn.

    Paul, I'm beginning to envy you with that vibratory compactor!

Share This Page