Prep for bitumen concrete floor

Discussion in 'Subfloor Preparation' started by Rocks100, Apr 17, 2024.

  1. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi All, seeking some advice please.

    Will be laying a 20mm engineered floor on top of an old concrete floor which had old parquet stuck down with bitumen. The new engineered floor will be floating on top of say a 12mm rubber/foam matting, flat is on 5th floor in large building.


    If moisture isn’t a problem do people think just an SBR primer over the bitumen remains will suffice and then SLC (not sure if has to be latex one or if water based is ok) with maybe Sika DPM on top (cheaper than the Ardex or Fball options) or is it worth going with the Ardex/Fball options?

    The area is approx 70sqm so cost is a factor.

    Many thanks in advance!



    Just conscious of not spending on the pricey /Faball options if they’re overkill.



    Appreciate any thoughts!
     
  2. merit

    merit Well-Known Member

    8,011
    1,642
    113
    Ardex NA direct without a primer
     
  3. dazlight

    dazlight Super Moderator

    6,882
    1,626
    113
    You floating the wood
     
  4. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, yes we are, although have got a problem as after taking up the floor we found there are cables, so not sure what to do now, the engineered floor will be 20mm thick and was hoping to add say a 10mm sound proof foam Matt underneath as underlay.
    At least there are no moisture issues, all is dry.

    Flat is over 70sqm so conscious of cost if using Ardex NA
     

    Attached Files:

  5. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, thanks for the tip, only problem is we have found cables underneath the old floor so would need approx 20mm, will be very costly with NA, old floor is dry, no moisture issues so hoping for a cheaper option.
    Thanks
     
  6. Rocks100

    Rocks100 Member

    18
    0
    1
    hi, yes indeed, posted further info below, thanks!
     
  7. dazlight

    dazlight Super Moderator

    6,882
    1,626
    113
    You could use Tremco NA. Bit cheaper.
     
  8. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, thanks for tip but to honest it seems like price looks quite similar.

    Assuming we need to go as much as 20mm am I correct thinking would also need to add Ardex course aggregate as well, could we pour 20mm in one go or would we have to do 2 layers of 10mm?

    Also assume we don’t need primer using NA?

    One last query, as we will be losing height I don’t think would have space for a thick soundproof mat, do you think a 5mm cushioned underlay might suffice?

    Much appreciate the advice!!!
     
  9. Rocks100

    Rocks100 Member

    18
    0
    1
    Sorry forgot to ask, would a Mapei SLC be ok by any chance, I know it would be water based but is a fair bit cheaper, thanks!
     
  10. dazlight

    dazlight Super Moderator

    6,882
    1,626
    113
    No mate.
    You defo want a latex so -
    Ardex na
    Fball pro flow
    Mapei na
    Tilemaster pro flow
    Uzin gold
    Tremco na
     
  11. dazlight

    dazlight Super Moderator

    6,882
    1,626
    113
    Or move the cables and do no screeding
     
  12. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, if only, the old bitumen later is far too bumpy, definitely needs a screed.

    it’s just having 20mm screed and then some underlay min 5mm and then a 20mm floor is really going to add lot of height which might be problematic with thresholds etc..but may not have a choice ‍♂️

    Am thinking of chasing channels into the floor to hide the cables, but would be a crazy dusty job, would ideally have to buy a wall chaser.
     
  13. Rocks100

    Rocks100 Member

    18
    0
    1
    Many thanks! :)
     
  14. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, I just wondered also is there a big difference between the Mapei Latex plan and NA version apart from just the reduced smell?

    Many thanks!
     
  15. merit

    merit Well-Known Member

    8,011
    1,642
    113
    Surely it would be cheaper to get the cables removed.
     
  16. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, the cables are a live installation, no where else for them to be placed I guess unless you start chasing into walls ‍♂️
     
  17. dazlight

    dazlight Super Moderator

    6,882
    1,626
    113
    The na has better polymers in it to help it bind to the bitumin adhesive and has a lot less compression strength.
     
  18. merit

    merit Well-Known Member

    8,011
    1,642
    113
    I dont think you should have live cables under your floor?
     
  19. Rocks100

    Rocks100 Member

    18
    0
    1
    Hi, as long they are in screed then I believe it’s acceptable, beside I think we will cutting some channels in the floor to hide them, also the client isn’t going to do a re-wire so has to stay as is.
    Thanks
     
  20. dazlight

    dazlight Super Moderator

    6,882
    1,626
    113
    Looks like it’s ardex na then.
     

Share This Page