Hollow spot in middle of new laminate floor

Discussion in 'Wood' started by CJC, Jul 20, 2021.

  1. CJC

    CJC Member

    8
    0
    1
    Hi All.
    New to this forum, so be gentle with me?
    I’ve just had new conservatory built, new slab, insulation and screed.
    Checked over the screed before laying 12mm klick laminate ex B&Q, but obviously not well enough.
    I was about half way through the 11 packs of boards when I cam across a hollow about six mm deep.
    This was on top of the green wood pulp underlay (also ex B&Q) that I was advised would give some more valuable insulation to the Conservatory floor!
    The builder said “……..it’s a bit too late now to get the screeder back to latex it, here’s some thin polystyrene foam underlay, cut some strips and add as necessary”
    This worked OK for a few weeks, but it’s starting to bounce and squeak, and il concerned it’ll start to split/separate soon.
    Query……
    Can I buy a suitable self mixing two pack adhesive, drill a small hole through a convenient knot, and slowly inject it into and hope it seeps sideways, to fill out the void?
    Any recommendations on any alternative methods?
    Any recommendations on most suitable two pack adhesive?
    Or am I just plain and simple, bloody dreaming?
    Remember, be gentle!!!
     
  2. dazlight

    dazlight Super Moderator

    6,259
    1,494
    113
    Take it up and start again. Who screeded the floor.
     
  3. Rugmunching

    Rugmunching Well-Known Member

    2,931
    504
    113
    Out of interest how long was it between the new slab and laminate being laid?
     
  4. Paul webb

    Paul webb Well-Known Member

    786
    90
    28
    If you really wanted to go down that route, take a look at uzin rk37,but as Daz said, you'd be better taking it up and sorting it out properly
     
  5. CJC

    CJC Member

    8
    0
    1
    Daylight. Are you saying take it ALL up, and start again.
    That would involve removing one side of the Roos skirting, and a lot of work.
    Why do you not rate the idea I proposed if a repair with two pack resin?
     
  6. CJC

    CJC Member

    8
    0
    1
    Slab, 16-17 weeks, insulation and screed, about six or seven weeks of mostly dry weather with the aid of a hired super site fan to keep the air moving. Moisture test was way OK!
     
  7. dazlight

    dazlight Super Moderator

    6,259
    1,494
    113
    Yes as you used the wrong underlay on a new concrete floor.
    The screed will still be releasing moisture so a underlay like the duralay should of been used with vapour tape.

    the resin idea would be ok if the floor was glued but as it’s floated it could still to the laminate underneath and stop it expanding
     
  8. CJC

    CJC Member

    8
    0
    1
    Sounds ideal Paul........
    -Removal of hollow spots
    -Excellent penetration and wetting properties
    -Filling cavities.
    Sounds like a good possibility
    Certainly worth a try for just drilling a hole and getting a syringe to push some in, as opposed to stripping at least 50% of the floor to get to the hollow and replacing the skirting, and possible damage where skirting's been ST1'd to the lined walls. Can't really see that as a "best" option. If it fails then Yes, THEN strip it?
     
  9. CJC

    CJC Member

    8
    0
    1
    Hi Dazlight. Are you saying that the slab releasing moisture is causing one area of less than a half a square meter if an 18 sq met floor to sink?
    It's in exactly the spot I put in the thin foam pieces as a packer, as recommended, and doesn't seem to be squeaking or bouncing anywhere else?
    But I will go back to B&Q and interrogate the flooring sales person again!
     
  10. CJC

    CJC Member

    8
    0
    1
    You state"......the resin idea would be ok if the floor was glued but as it’s floated it could still to the laminate underneath and stop it expanding......", but it will only bring that one small hollow and a bit adjacent to it that would stick to the slab. And anyway, although it's recommended a good margin is allowed for expansion, HDF is a relatively inert product and shouldn't expand THAT much, should it?
    Appreciate your input, Thanks!
     
  11. Paul webb

    Paul webb Well-Known Member

    786
    90
    28
    We will always recommend doing the job properly, but if you want to attempt a repair, then that's your choice, i would probably suggest injecting the resin below the laminate but on top of the underlay, being fibreboard there's a better chance of the top layer of the board breaking away if the floor needs to move, rather than having a fixed point to the concrete, ideally drill through a knot if possible then use a laminate repair kit to fill the hole
     
  12. CJC

    CJC Member

    8
    0
    1
    Thanks for that Paul. Do you have any ideas about what to use to inject into the void, as I assume the laminate repair kit is just to fill/repair the actual hole?
    For that matter, any recommendations for both filler and which laminate repair kit? Rgds Chris
     
  13. AngryAndy

    AngryAndy Well-Known Member

    306
    108
    43
    I wait with bated breath for your next post telling us how interrogating the B&Q flooring sales person again went for you!!
     
  14. CJC

    CJC Member

    8
    0
    1
    Well, the guy I spoke to in charge of the flooring dept has now moved on, and the guy that's now in charge, I think is still at school, part time at B&Q!
    I'm joking of course, but he managed to avoid saying it was right or wrong to use wood pulp underlay, probably didn't want to drop his (ex) colleague in it?
     
  15. dazlight

    dazlight Super Moderator

    6,259
    1,494
    113

    No I’m not saying that. I’m saying you shouldn’t use fibre boards on concrete as it’s terrible underlay. You put in the opening post you had a new slab put in?

    The sub floor should of been checked for SR1 standard ( no gap more then 3mm over a 2m straight edge ) before the floor was laid.
     
  16. Paul webb

    Paul webb Well-Known Member

    786
    90
    28
    The uzin comes with a nozzle that goes into the drilled hole,i think b&q do the repair kits,you get either 4or6 blocks and a little soldering iron type thing, you can mix the colours together, to get a match, it's possible to get an almost invisible repair
     
  17. merit

    merit Well-Known Member

    7,143
    1,515
    113
    90% of subfloors new or old need levelling compound. Especially if your floating a floor over it. It’s take up, latex level and refit


    Sent from my iPhone using Tapatalk
     

Share This Page