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Pavers on concrete

Discussion in 'Hardscaping' started by EliteImpressions, Sep 24, 2005.

  1. EliteImpressions

    EliteImpressions LawnSite Member
    from Jersey
    Messages: 215

    I will be doing a large patio next year for my house. Total size will be about 40' long and 15' wide. I was just reading that you can mortar the pavers onto an existing concrete slab. The final cost would be about the same if I had someone come out and pour the concrete for me. I wouldnt have to excavate or worry about moving a few tons of base material either. Has anybody ever done this, and if so, will the quality be the same.

  2. mbella

    mbella LawnSite Bronze Member
    Messages: 1,284

    Elite, we have paved over concrete. The first thing I do is find out how long the existing concrete has been in place. The second thing I do is inspect the existing concrete. If it has been in place for a number of years and is in good shape (no cracks, settlement, proper drainage, etc.), I'd do it. I never offer a warranty on this application, but I do it.

    If your existing slab has been installed for a number of years, is in good shape and drains properly, I don't see a problem.

    Also, no need to mortar the pavers. Dry lay the field pavers and use paver adhesive to adhere the perimiter pavers to the concrete slab. Sweeping sand into the joints is enough to achieve interlock within the field of pavers.
  3. Rex Mann

    Rex Mann LawnSite Senior Member
    Messages: 621

    We overlay about a 1000 square feet of concrete a week.
    Mikes' recommendations on accessing the quality and integrity of
    the concrete is very sound advice, especially if you are located in
    a freeze-thaw environment.

    We like to screed out a 1/2-inch of concrete sand, if we have enough room.
    This way we eliminate the chance of the pavers rocking. They seem to have a tendency to do this on control joints. Then we use mortar to affix the perimeter pavers.

    If we can not use sand, they are installed as Mike described. We then use dried bagged sand, which is finer and makes it easier to fill the entire depth of the joint.



  4. EliteImpressions

    EliteImpressions LawnSite Member
    from Jersey
    Messages: 215

    If I was to use the concrete slab, I would be having that put down a few months before I install the pavers. Is this a good idea, or should I just go the normal route and excavate, lay material, base, etc? I just figured having someone lay the concrete would be easier than me having to excavate and put down a base.
  5. Dreams To Designs

    Dreams To Designs LawnSite Bronze Member
    Messages: 1,406

    There is mo need or reason to pour concrete to lay pavers, unless you have a serious soil or settling issue. The tried and true method of removing the soil, geo fabric, base material and lots of compaction will suit you fine. As Mike said, he will not offer a warranty on laying pavers over concrete because you do not have control of what the concrete will do. It can heave and will crack, possibly affecting your pavers. Easier is not always better.

  6. mbella

    mbella LawnSite Bronze Member
    Messages: 1,284

    Elite, I thought the pad was in place. No way would I plan to pour the pad and overlay it with pavers.
  7. EliteImpressions

    EliteImpressions LawnSite Member
    from Jersey
    Messages: 215

    Thanks for the reponses. I kind of figured that but I wanted to double check since it would save me a lot of time by using the concrete.
  8. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Messages: 6,601


    No existing concrete - do not pour concrete :)

    Existing concrete, and all is well, and it's at the correct grade (so pavers are not higher than the threshold into the dwelling), then go over it if you so desire.

    And to go one step further, while on the subject - just drill holes and anchor your restraint in the concrete. No mortar needed!
  9. NNJLandman

    NNJLandman LawnSite Bronze Member
    Messages: 1,306

    I would never put pavers over top of concrete. To many things could go wrong. Just seems like a pad idea. We always rip up the concrete and put down the pavers.

  10. mbella

    mbella LawnSite Bronze Member
    Messages: 1,284

    Jeff, we do it on stoops all the time. If the concrete is in good shape, has been in place for a number of years and you have the clearance like DVS said, there's nothing wrong with it.

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