Concrete Pavers next to Concrete Slab - Settling?

Discussion in 'Hardscaping' started by Akshue, Apr 16, 2009.

  1. Akshue

    Akshue LawnSite Member
    Messages: 20

    OK guys, got a quick question here... This is my first "real" project as a homeowner.

    We have an existing concrete slab patio that is in great shape, but we are expanding it with concrete pavers. We intend to have the concrete stained to come close in color to the "inside" pavers once we are finished.

    I am currently excavating (not easy, being a stay at home dad of a 6 month old! Need to get work done during naps and such...) and should be ready by the weekend. The 3/4" TB comes on Tuesday (5 days or so), and I hope to have that finished by thursday. Sand and pavers hopefully a few days after that, but I'm planning on it taking 2 days or so.

    My 3/4" TB will be about 6" deep, the sand about an inch.

    My question is about getting the pavers close to level with the existing slab. How much can I expect them to settle in the sand? Would you reccomend screeding the sand first, hand-tamping, and re-screeding to lower the chances of things settling out? How much higher than the existing slab would you reccomend for things to end up level after the plate compacter goes through?

    With a baby that is growing into a toddler, I want to avoid any sort of tripping hazards; not to mention, I think it would look far better if things were nice and level at the transition.
  2. Bru75

    Bru75 LawnSite Senior Member
    Messages: 582

    If your pavers are 2 3/8" thick, compact your gravel bed to 3" below the edge of your concrete. Screed your sand using 3/4" galvanized pipe and a straightedge and lay your pavers. This should put the pavers about 1/4" high. Then run a compactor over them. The sand should compact to a level that is really close to your slab. Don't compact the sand first.
    Be sure to compact your gravel base in layers, and compact it good!
    If your pavers are a different thickness you will need to adjust for that.
    I don't know if a 6" base is enough for Wisconsin winters, maybe somebody closer can advise you about that.
    Stay at home dad? You're tougher than me, I have two kids and taking care of them is harder than going to work!
    Hope this helps.
  3. Akshue

    Akshue LawnSite Member
    Messages: 20

    Thanks for the info. I'll plan on having it up by 1/4".

    As far as the depth goes, it will be about 6" minimum - closer to 7 in most places (8 in the corner when I misread the bubble and did a 3/4-1" drop instead of 1/8... just read the wrong side of the bubble, stepped back and it didn't look quite right)

    I was planning on laying down an 3" layer of gravel over the geotex, power-tamp, and then the rest, screeding that flat and pitched properly, and re-tamping.

    How much should I expect the gravel to compact the second time around? Should I lay it out loose 1/4" or so over my 3" line, expecting that to also compact down? Or is it more solid than that?

    As far as the stay-at-home dad thing.... Yes, it's pretty rough. It was kind of forced upon me due to the plant where I worked at closing, but hey - as long as uncle sam wants to pay me a bit of $$$, I'll save the daycare expense and enjoy it while I can. Since I am a "displaced worker", I actually get a full year of unemployment, and more if I go back to school to learn a new trade.
  4. Bru75

    Bru75 LawnSite Senior Member
    Messages: 582

    Getting the base to the right level will take a few tries. Add gravel, tamp, measure, and repeat until the desired level is reached.
  5. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Messages: 1,174

    6" of base will be plenty of base, but make sure you spend extra time compacting against your concrete slab.
  6. Akshue

    Akshue LawnSite Member
    Messages: 20

    Was planning on that, next to the slab... Figured it would be a little rougher. I spent quite a bit of time today going around it with a screwdriver and hammer to knock off all of the rough edges, and I plan on trying to compact and then backfill under the slab as much as possible.
  7. AllHardscaping

    AllHardscaping LawnSite Member
    Messages: 77

    run geotextile under your gravel base and up the side of the concrete. This will keep the paver system contained. I always see pavers up to concrete and they always settle. The water gets between the 2 systems and settles the gravel under the concrete (I guess concrete guys dont compact as much as paver guys. I have seens some throw 6 inches and run the compactor once over the top) then the sand and gravel from your paver system washes in to fill that void. I have repaired jobs that have had the whole 6cm paver wash under the concrete. You can use an adhesive to keep the geo on the concrete edge to make it easier to throw gravel down and compact. Just be sure to keep the geo tight

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