Tiling a floor onto old stone flags/bare earth.

We have an old stone floor, with a few gaps between them, which I believe is laid straight onto the bare earth. I don't want the flags so need to cover it before tiling with large wood effect tiles. Do I put a damp proof membrane down first before a self levelling compound or would you advise putting something down to seal the floor before adding the membrane and SL compound.

Asked by Sean on 13th Oct 2025
Expert Trade Answers
"I suggest you level it with latex leveling compound and then you can put it on top. waterproofing"
Answered on 13th Oct 2025 - Member since Jan 2023 - report
"Moisture test the floor first but will more than likely need a dpm one coat two part solution (damp proof membrane) get a moisture tolerant self levelling compound and sandwich coat the membrane. Compound/dpm/compound. Alternatively uplift stone, sheet membrane, concrete/dpm/compound. Hope this helps."
Answered on 13th Oct 2025 - Member since Apr 2024 - report
"If your old stone flags are laid directly onto bare earth, I would definitely recommend installing a proper damp proof membrane before any tiling. This will prevent rising damp and moisture from damaging the adhesive or tiles later on.

The best approach would be:
1. Clean and stabilise the surface, filling any large gaps between the stones.
2. Lay a DPM (damp proof membrane) sheet across the entire area.
3. Apply a self-levelling compound on top to create a flat, solid surface for tiling.
4. Once fully cured, you can proceed with tiling using a flexible adhesive suitable for underlayment with slight movement.

Avoid tiling directly onto the stone or bare earth — it won’t last long and can lead to cracking and damp issues.

— Gustavo | MG Elite Maintenance"
Answered on 9th Nov 2025 - Member since Nov 2025 - report
"if the old stone flags are laid directly onto bare earth, it"s important to manage both moisture and stability before tiling."
Answered on 29th Oct 2025 - Member since Oct 2025 - report
"Maybe fill gaps with concrete and seal with resin , best to send me photos"
Answered on 13th Oct 2025 - Member since Aug 2025 - report
"I would lay waterproof rein then latex before laying floor"
Answered on 13th Oct 2025 - Member since Oct 2024 - report
"Hello, based on your description I would suggest filling the voids, screeding the floor with an epoxy membrane then laying your tiles. If the epoxy is too costly for you then you could use a standard water proofing such as thompsons.
Without seeing it is hard to give a definitive answer but that is my best opinion in the circumstance.
Kind regards
Simon"
Answered on 14th Oct 2025 - Member since Oct 2025 - report
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