How to fill this hole in my kitchen

Discussion in 'Builders' Talk' started by Devlin Thornicroft, Sep 22, 2021.

  1. Devlin Thornicroft

    Devlin Thornicroft New Member

    Hi all

    We had a massive leak in a newly purchased house which caused all sorts of damage. I found that even after clearing everything up there was a persistent damp patch on the kitchen floor, and horrible white mould growing - see pics. I got a handyman in with a jackhammer and cut out a section of the floor. Luckily it wasn't another leak underneath but mostly likely trapped moisture in the concrete and what was underneath it.

    I now need to fill this hole up, and get it back into a position where the kitchen fitters can level the floor. My question is - what is best to fill this hole up? Ideally I want something that doesn't absorb moisture. It's an old house probably with no DPM. Would gravel, and then concrete be OK?

    White Mould.jpg Damp Patch.jpg Hole in floor.jpg
  2. Bob Rathbone

    Bob Rathbone Screwfix Select

    What concerns me about this is how far does this hole go and is it the only one. You may need to dig up the whole floor and re lay it.
  3. Devlin Thornicroft

    Devlin Thornicroft New Member

    Hi Bob

    Only goes as far as you can see. I haven’t dug under and in, only down. No other holes. Not sure why you think I would need to dig up the whole floor? The plan ultimately is to level the floor and then install laminate.
  4. DIYDave.

    DIYDave. Screwfix Select

    Isn’t it common for old quarry tiled / stone floors to be laid directly onto the dirt with no DPM of any type installed ?

    Do we presume that the massive leak was due to damaged pipework under the floor and this has now been rectified ?

    If so, fill hole with compacted hardcore and concrete over at 100mm depth and finish flush with surrounding tiles

    You don’t say what floor finish your now looking at, just mention floor levelling

    So once the hole has been filled and concrete cured, would be a good idea to lay a membrane over the lot - either liquid type of poly sheet

    Can then pour self leveller over either, obviously following correct prep for either DPM used

    Im diy only so see what others say !
  5. Devlin Thornicroft

    Devlin Thornicroft New Member

    Hi DIYDave

    Sorry, I should have been clearer - the leak came from above not below. But the leak took place over at least two weeks as no one is living there. Yes, from what I’ve read and my gut is telling me there is no DPM under all this. I was thinking about using a liquid DPM before the final flooring is fitted but wasn’t sure whether the liquid DPM goes before or after the levelling compound.
  6. DIYDave.

    DIYDave. Screwfix Select

    Hi there and yes, I had assumed that the leak was below the floor !!

    Look at the edges where the floor has been cut and you may be able to see evidence of a DPM between the layers / but good chance not

    I’ve done similar with a quarry tiled porch, showing a little damp in one corner, that I prepped and tiled over with porcelain. All good some 8 years later

    Thoroughly clean existing tiles, sweep/hoover then mop to degrease and remove grime - allow to dry

    Brush/roller on 2/3 coats of liquid DPM. Blackjack is one brand, Sika another, take your pick but follow manufacturers instructions always

    Then 2 coats of diluted SBR @1-4 over the DPM - allow to dry

    Now ready to pour your self leveller

    That’s the method I used after taking advice from Mapei, as I used their Ultimate levelling compound (SF 4377v)
  7. Devlin Thornicroft

    Devlin Thornicroft New Member

    Amazing. This is solid advice. Just what I was looking for actually. Will research those methods and formulate a plan.

    Thank you.
  8. DIYDave.

    DIYDave. Screwfix Select

    No problem, hopefully I’ve given you solid advice !

    Easy these days to look up online all the above products and their data sheets so research is a breeze

    As I did with Mapei, all companies have a technical advice line and once you get through, are usually happy to talk through the correct procedure with you but will obviously only apply when using their own products

    Good luck with the house
  9. ElecCEng

    ElecCEng Screwfix Select

    Sink in a pop up wine cooler, you know you want to ;)
    CGN likes this.
  10. CGN

    CGN Screwfix Select

    I would :D
  11. CGN

    CGN Screwfix Select

    DID is correct, many are laid on a dirt/ash base. All down to how much upheaval and money you want to spend. I’ve ‘codged’ a few up over the years tbf when it wasn’t worth the hassle.
    DIYDave. likes this.
  12. GRH

    GRH Member

    Hmmm. It looks like something Miss Marple should investigate, a hole that shape.
    ElecCEng likes this.

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