Re leveling subfloor advice please

Discussion in 'Subfloor Preparation' started by savage87, Mar 7, 2017.

  1. savage87

    savage87 Member

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    Hi to everyone!
    I'm Alex, just another DIYer.
    I have wet underfloor heating in 50mm screed in my living/dining area, I've leveled the screed with Bostik Cempolatex self leveling compound.
    When I done it about a year ago I didn't have a spiked roller and in placed it kind of bubbled and it's not exactly perfect.
    Now I want to redo it and put some LVT down, to do that the subfloor needs to be near enough perfect.
    Can someone please let me know how can I acheive a good enough subfloor so I can lay the LVT?

    What compound should I use?
    What special tools do I need?
    Do I need a primer?
    Should I do anything to the existing subfloor?
     
  2. merit

    merit Well-Known Member

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    You would probably be better off using jumpax if you are not skilled with levelling compound. That cempolatex of one of the worst levelling compounds I've ever used. They actually tell you to prime the subfloor with pva?


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  3. savage87

    savage87 Member

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    I've used PVA on the screed before using the compound, It's stuck well a couple of hairline cracks here and there but nothing major.
    Thanks!
    Any other advice?
     
  4. merit

    merit Well-Known Member

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    Yeah, stop using pva as a primer


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  5. merit

    merit Well-Known Member

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    Jumpax heatpack will give you a perfect subfloor for lvt. If your going to use a levelling compound you will need to get it perfect or it will show everything. I don't think it's a diy job


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  6. savage87

    savage87 Member

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    Thanks for the advice, what primer do you think I shoud use?
    I've looked at jumpax and it looks a bit thick and I don't know what the tog rating on it is, I've looked on their website but I couldn't seem to find it.
    Any other compounds that you would recommend?
     
  7. Spacey

    Spacey Super Moderator Staff Member

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    I'd check your original screed is actually fully bonded before you do anything
    It would still have to be half decent to lay jumpax over it especially if you've got high and low spots which I'm guessing you do
    You'd savery your self a lot of time and hassell if you get a professional in
     
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  8. savage87

    savage87 Member

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    I haven't put anything on the self leveling compound, just the bare floor, it hasn't come loose in the year that it's been down. I'm quite a competent DIYer and I'm trying to save some money wherever I can.
    Wouldn't the jumpax have a high impact on the heat coming through the floor?
     
  9. Rugmunching

    Rugmunching Well-Known Member

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    Oh dear...o_O
     
  10. Spacey

    Spacey Super Moderator Staff Member

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    You haven't put it under any stress yet !
    If you screed over it and get a good bond then it's going to pull on the original screed Then you'll find out
     
  11. savage87

    savage87 Member

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    OK, I understand, I need to do something as I want put the LVT down but I need to sort out the subfloor beforehand. Jumpax doesn't work with wet underfloor heating and I will need to latex the floor again or sand it, or something, anything.. Anymore advice is highly appreciated! Thanks!
     
  12. merit

    merit Well-Known Member

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    Jumpax heat pack has a tog rating of 0.5 but as Spacey says, if the floors not flat it will bounce under foot. Why can't you use the same levelling compound again? Bostik should really make a primer for their levelling compounds


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  13. Spacey

    Spacey Super Moderator Staff Member

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    Ardex NA then Prime with P51 You need a good mixing drill Spike roller and I always use a pin level rather than a trowell It gives a better result and it's quicker and easier as you stand ingredients up rather than crawling about.

    Don't forget the feather
     
  14. Spacey

    Spacey Super Moderator Staff Member

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    Ingredients WTF ????

    WHERE'S THE EDIT BUTTON GONE

    SORT IT OUT MAN :mad::mad::mad:
     
  15. savage87

    savage87 Member

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    Thanks! Great post!
    I have an SDS Drill with a paddle mixer drill bit. Would that do?
    So far, so good, I'm happy to buy the Arditex NA, P51, spiked roller, and a pin level.
    I had a look at the instructions for the Arditex NA and it does say it you don't need to use primer, given the situation, would it hurt to prime it?
    Why do you use the P51 after the Arditex NA?
     
  16. Spacey

    Spacey Super Moderator Staff Member

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    Always prime
    P51 prior to laying the latex
     
  17. Spacey

    Spacey Super Moderator Staff Member

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    I ment "Ardex NA then" as the answer
     
  18. merit

    merit Well-Known Member

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    Jumpax does work with wet underfloor heating? But if your set in using a self levelling compound you should defo use a primer first or you will get 'hairline cracks' and pinholes. These will show through LVT.


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  19. Profflooring

    Profflooring Well-Known Member

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    Before the levelling repair the cracks if the are very bad Ardex a45 or feather. Use floor grinder, big plate machine to make it smooth( you can hire one) and use spirit level to locate the higher and lowest parts. The higher arias need to be grind it, don't worry for the lowest arias. If you think is looks good, you are ready for floor levelling. Will say the same as the Aridtex NA. This is very strong levelling compound ( good mix, spiky roller - I am using pin leveller too) and you need to use machine to sand it down with sand big grid sand disc. Make sure is white colour mean perfect dry. If is darker colour is mean is wet and the machine will be over load it and will be kind or wrestling with the machine which is very powerful and make sure you get good balance when you using it. Then spirit level again and must to be flat everywhere. You can use a45 if you are not happy with lower arias. This is the professional way.

    www.birminghamfloors.co.uk
     
  20. savage87

    savage87 Member

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    Thanks for your reply, very helpful!
    I'm still really templed to do it myself, I got a quote for 30sqm 450 pounds to sort it out and then I started looking into doing it myself, I now have a second quote of 300 pounds, which is kind on near enough what I'm going to be spending on materials and additional tools.

    First quote was to prime floor prior to trowelling, 2 part levelling compound, trowel floor with feather finish, 3 visits.
    Second quote is to acheive the same finish to receive LVT, 1 visit, sanding prior to priming and levelling. Stopgap 300 to be used.

    Any comment on these quotes, does the second one sound to good to be true?
     

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