Pillar on top of existing concrete slab >>

Discussion in 'Hardscaping' started by platinum, Sep 1, 2011.

  1. platinum

    platinum LawnSite Member
    Posts: 170

    I have an existing stamped concrete slab that I would like to put some pillars on the corners. I have 2 questions.

    1. Should I be concerned with the weight on the ends of the slab?
    2. How do you adjust for the grade of the concrete for run off. Its slight but it would be noticeable. I was going to put some mortar at the bottom for the course layer to level it out. Is that sufficient?
     
  2. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Posts: 6,403

    1) No
    2) Yes
    Posted via Mobile Device
     
  3. Crusher Run

    Crusher Run LawnSite Member
    Posts: 69

    Use grout NOT Mortar. Big difference.

    What does the stamped slab have for reinforcement?
     
  4. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Posts: 1,177

    Mortar will be fine and grout will get a little pricy if you need to use a lot. Did you mean thinset or grout?
     
  5. Crusher Run

    Crusher Run LawnSite Member
    Posts: 69

    Cementious grout. We get 50lb bags for about 19 dollars, and it's a 10,000 psi mix!! It's Harris Construction Grout. Non shrink non metallic, it's real good stuff. We use it for our leveling plates, which support the steel in large commercial buildings.

    Mortar is more about bond strength, flexibility, durability, with the strongest type (M type) being 2,500 psi.

    If you just need compressive strength, then grout is a better choice.
     
  6. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Posts: 1,177

    Really, that's pretty interesting to know. 10K psi strength is good. :)
     
  7. Crusher Run

    Crusher Run LawnSite Member
    Posts: 69

    Yah, just in case his pillar weighs like 75,000 lbs lol
     
  8. platinum

    platinum LawnSite Member
    Posts: 170

    A little more info on the slab. it's about 400 sq/ft, 4 inches think, has a rebar grid for reinforcement and sits on about 10,000 lbs of limestone, no joke. Yard is sloped pretty bad so we build it up allot.

    It's about 3-4 years old now and I'm starting to see some settling on the front section of the slab. This happens to be where the pillars would be going as well. It sounds like the extra weight is not a problem but could it make that section settle faster? The Pillars will be around 3 foot tall.

    appreciate all the feedback
     
  9. zedosix

    zedosix LawnSite Silver Member
    Posts: 2,628

    What about cutting out the small section where the pillar would end up. This way you dont need to worry about the slope or settling.
     
  10. STL Ponds and Waterfalls

    STL Ponds and Waterfalls LawnSite Bronze Member
    Posts: 1,177

    I don't remember what you said the pillars will be made of, but that can play a part. Full veneer will be a lot heavier than a cultured stone etc.

    Plus, what Zedo mentioned is a good idea!
     

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