Engineered Wood floor prep

Discussion in 'Subfloor Preparation' started by Ahriman, Sep 11, 2021.

  1. Ahriman

    Ahriman New Member

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    Hi all, I've been reading all the advice I can find on this forum over the past few months and it's been really useful so thank you!

    I'm planning on glueing down an engineered wood floor in the living room of our 1950s ex council house. I pulled back the carpet and found old marley tiles stuck down with black bitumen adhesive on top of a concrete slab. I've had them tested and they have been found to contain white asbestos. House has a dpc but is over 60 years old, had no problem with damp but have decided to put down a liquid dpm just in case. Decided to use Ardex products and have been in contact with one of their reps for some advice, they've recommended the following:
    1. Remove marley tiles (with the adequate precaution) scrape up any of the adhesive that's soft/sticky
    2. NA over the concrete and any remaining adhesive.
    3. DPM 1C
    4. R3E sand blind
    5. NA
    6. Glue down engineered wood after 48hrs
    Just after some clarification to whether I've interpeted their advice correctly and that this sounds like the correct approach. Anything in particular I should watch out for?

    Any recommendations for the adhesive to glue down the engineered wood over the final coat of NA? Ideally I wanted to use another Ardex product so that I'd know it'd be compatible but it seems like they no longer make their version.

    I'd really appreciate any advice.
     
  2. dazlight

    dazlight Super Moderator

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  3. Simon Grimley

    Simon Grimley Well-Known Member

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    It might be worth looking at UZIN L3 Gold. It’s screed and DPM in one so saves a lot of work.

    I’ve personally not used it but the rep just specified it on one of my jobs as the floor was damp.
     
  4. merit

    merit Well-Known Member

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    Be careful with l3 gold. It’s not great with damp floors. I thought it was more for construction moisture? We used it on a old damp floor I a commercial property in London and it failed. Apparently it wasn’t suitable for that type of damp


    Sent from my iPhone using Tapatalk
     
  5. Simon Grimley

    Simon Grimley Well-Known Member

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    Interesting. I’m quoting on a domestic LVT job with damp and it was recommended by my rep…
     
  6. Neilydun

    Neilydun Well-Known Member

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    Had the same. Very big job, very far away, very many problems.
     
  7. dazlight

    dazlight Super Moderator

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    Rule a thumb for us is if it doesn’t have a Dpm under it. So every concrete floor pre 1965 ( even though we treat that as pre 1980 ) we use a epoxy Dpm
     
  8. Ahriman

    Ahriman New Member

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    Thanks for all your replies. Decided I've be going belt and braces and following Ardex's advice.

    I've been monitoring the air relative humidity the past few days and getting a reading of about 72%/74%. I've haven't begun any work yet and I'm wondering if these high values are being caused by the lack of dpm in the old concrete floor? Not sure if I'm over thinking it?
     
  9. UZIN L3 Gold can be recommended if you dig up the old concrete floor, install a new DPM and lap up edges before replacing the concrete slab. For better, isolate the dampness fully in the floor using a surface DPM.
     

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