Grinding before self-leveling

Discussion in 'General Flooring Discussion' started by Timo, Mar 15, 2018.

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  1. Mar 15, 2018 #1

    Timo

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    Hi,

    I am new to floor work. I am going to self-level my basement concrete floor before putting Barricade subfloor tongue and groove panels and luxury vinyl on top of that. I looked at Mapei or Sika self leveler compounds and both manufacturers say to grind the floor to CSP #3 profile.

    I renter Husqvara PG280 single head grinder to do the job. As I can't really tell what's CSP #3 vs #4 etc I can't definitely say whether the floor has been ground to the appropriate level of "roughness".

    My question to the knowledgeable folks here is this - how crucial is it to have cement ground exactly to the level that the manufacturer of the self leveler recommends? What can potentially happen if the floor is not sufficiently ground or not ground? I am applying self-leveler across the entire surface.

    THank you much in advance.
     
  2. Mar 16, 2018 #2

    Ernesto

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  3. Jul 30, 2018 #3

    Timo

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  4. Jul 31, 2018 #4

    Ernesto

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    Just about any diamond head grinder will get ya to a csp-2 -3. The reasoning is they don't want you going over a really smooth surface or a surface with bond breakers on it like paint and old glue or it won't grab and could come loose . Make certain you use any primer they may recommend. All SLC's need a primer as it helps the stuff flow and won't curl at the perimeter.
     
  5. Jul 31, 2018 #5

    Timo

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    Thanks, Ernesto. I included a picture of what it looks like now. Not perfect grinding but it was a pain to get it even to this point. Do you see any concerns with how it is now?

    Thanks
    Michael

    Floor.JPG

     
  6. Aug 1, 2018 #6

    Ernesto

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    Looks great Timo. Why self leveler, not flat enough?
     
  7. Aug 1, 2018 #7

    Timo

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    Thanks.

    Well... there aren't really any huge peaks and valleys but all over the floor I have a number of minor imperfections. I already started laying barricade subfloor boards to just discover that I need to practically put shims under almost every single one of them. And in some spots no matter what I tried I still got a bit of give when I stand on the board. I believe there isn't anything larger than 1/4" but it would just drive me nuts if I stepped on a floor and it had give.

    Thanks,
    Michael


     
  8. Aug 1, 2018 #8

    Ernesto

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    Well SLC can really help but if your not experienced at it you can have the same issues. I only use it for small areas. In larger areas you really need a crew with a pumper and guys with golf shoes on pushing and raking it flat. Typically we go for flat not level. Big difference.
     
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  9. Aug 1, 2018 #9

    Nick

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    They made us use Football shoes at the Ardex training center .. You do need the guys and the pumper ..
     
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  10. Aug 4, 2018 #10

    Timo

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    My largest space in the basement is about 400 sq ft. What if I sectioned it off in areas of say 100 sq ft? Was planning to have someone assist wth mixing while I was poring and smoothing the cement.
     
  11. Aug 4, 2018 #11

    Ernesto

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    400 sf is doable with two people. Just have plenty of buckets ready to go. Make sure you use the required primer.
     
  12. Aug 5, 2018 #12

    highup

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    Two people who have done this before. ;)
     
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  13. Aug 5, 2018 #13

    highup

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    My sarcasm in the prior post was serious. I'd recommend 4 people who are somewhat good with mechanical thinking. Be sure everyone is all aboard from the beginning so that the process 'pours' fast and steady. A mini marathon of sorts.
    If you have one too many people, that's OK. One person not enough is a bad day.
     
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  14. Aug 10, 2018 at 5:33 PM #14

    Timo

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    Thanks, Gents. So is it a bad idea to try and separate the larger room into smaller sections with something like weather strips or something of sorts?
     
  15. Aug 11, 2018 at 1:05 AM #15

    Jon

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    What some of the guys here do is have big plastic rubbish bins full of water handy so that they can just scope the water out without having to fill the bucket of water each time
     
  16. Aug 11, 2018 at 4:34 AM #16

    Ernesto

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    Sure, you can nail down some wood to separate the pours but remember you need those edges to match up. Which it is why its kinda easier to just pour an entire room. However you could come in and grind down the height difference.
    There are methods like drilling in the concrete and molling screws set to the level your trying to achieve, and or then leveling to the tops of the screws or string set to the screws run across the room. It's kinda technical.
     
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