Self levelling compound over floorboards

Discussion in 'Builders' Talk' started by Jacopo, Nov 22, 2019.

  1. Jacopo

    Jacopo Member

    You read the wrong one

    this is the one I have used (can be poured between 3-40mm per lay), and there is no mention of using primer between coats

    https://cdnmedia.mapei.com/docs/lib...renovationscreed3240-uk.pdf?sfvrsn=ab6c8e97_0

    Anyway, the noise was there before the SLC was applied
     
  2. Jord86

    Jord86 Screwfix Select


    Riiiight........ that one however doesn’t mention multiple applications of the product though.

    No offence, but if the noise was there before why did you carry on with the latexing?

    Post a couple of photos up and indicate where the cracking is coming from.
     
  3. Jacopo

    Jacopo Member

    I don’t have an answer to that, I guess as it disappeared after walking on it, we assumed it wouldn’t come back every morning, plus we had already contracted the guy to do the latexing
     
  4. Jacopo

    Jacopo Member

    I can post some pictures but I can’t really tell you where the noise is coming from (everywhere?)
     

    Attached Files:

  5. wiggy

    wiggy Screwfix Select

    Did you butt the 6mm ply together?
     
  6. Jacopo

    Jacopo Member

    yes
     
  7. wiggy

    wiggy Screwfix Select

    And that sir is where your problem lies.
    You should have left a 5mm gap.
     
  8. Jacopo

    Jacopo Member

    I wish it was that simple, I could just cut through with the circular saw and create the gap, but a gap between something that is fixed down is not required

    I screwfixed very close to the edges
     

    Attached Files:

  9. wiggy

    wiggy Screwfix Select

    If you had glued it I would agree.
    But you're right in running a skill saw down the joins, its one way of hopefully sorting the problem out, albeit the desperate option.
    Basically what you have is a badly laid floor on top of a badly laid floor.
     
    Rad87 likes this.
  10. Jacopo

    Jacopo Member

    I welcome your opinion, but I’m not convinced; lack of glue might be the reason of the noise, but nothing to do with the gaps
     
  11. wiggy

    wiggy Screwfix Select

    Its the same when you lay roofing sheets, 5mm gap to deal with expansion.
    Think about the noises you started with, when did it get worse? after you laid the 6mm ply. You could have got away with putting a good bead of pu at the butts and got away with it.
    Botton line is you have a creaky floor. Your options are get a track saw and run it down all the joins or rip it up and start again or live with it.

     
  12. Jacopo

    Jacopo Member

    I just tried to run my circular saw through the joints of one sheet; I waited 24hours, I came back and stepped on it and it still makes the same noise (coming from other sheets)
     

    Attached Files:

  13. Jord86

    Jord86 Screwfix Select

    Not to dispute Wiggy but I wasn't convinced it was due to the lack of gaps unless you boarded tight to the walls, even then you said it was creaking before that so unfortunately I think you’re stuffed. Contact Mapei and see if you’ve any form of recourse with them for following their instructions, but I wouldn’t get any hopes up.
     
    wiggy likes this.
  14. Jacopo

    Jacopo Member

    The thing is that I think it’s the plywood that creaks, not the latex
     
  15. Jord86

    Jord86 Screwfix Select


    Look, you said it creaked before you levelled over but you still levelled it anyway, you used 15mm screws which are nowhere near long enough to secure anything, you used 6mm ply which in my opinion is no good for overboarding work, you didn’t glue the ply down with the screws, you used a leveller product that doesn’t state it’s suitable for another application of a second layer which you did, your dips in the floorboards were in the region of 30mm, you plyed it yourself to save money on labour so you’ve no recourse against anyone for a poor installation, and you went over the installers application with another layer, which whether it was suitable or not, you didn’t prime it anyway.

    I don’t know what answer you want other than take it all up or live with it. There’s no nice way to say it. It’s a bodged job on top of an unsuitable substrate, that wasn’t prepared properly at the beginning.
     
    wiggy and Abrickie like this.
  16. I have a similar problem with new extension; completely new floor. I've tracked the creak (I think) to where one or two joists rest on the brickwork in the end wall. Good news is that when furniture placed in the room, the weight is enough to keep the floor pressed down and stop the creaks. (otherwise I was considering making a hole through the cavity wall from the outside to pack up the joist :)
     
  17. Jacopo

    Jacopo Member

    I doubt this has anything to do with what I’ve done as yours is a new extension but, just checking:

    have you laid 6mm plywood over existing floorboards or used a self levelling compound over the plywood?
     
  18. loeogie99

    loeogie99 New Member

    Which model or brand you are using? I'm looking for the best budget circular saw for my steeling cutting work. I have read some reviews about it but need more help.
     
  19. Rob Wilson

    Rob Wilson New Member


    Thanks DIYDave! This is exactly the advice and affirmation that I was looking for - going to do exactly this! My floorboards are sound (well secured, no bounce, slightly uneven thicknesses here and there due to different boards being used over the years), but the whole floor slopes in one direction resulting in a 30mm difference from one side of the room to the other. Anyone got any good advice of what to use around the edges to stop the compound disappearing under the plasterboard? I've seen polystyrene edging or foam edging used but I can't seem to find the same stuff available to buy in the UK.
     

Share This Page