flooring problems

Hi guys

We are renovating the kitchen in our 1940's house, and have uncovered a few unexpected issues.

The kitchen is now empty, and we've removed ceramic tiles to reveal smaller quarry tiles. We also had lead piping from the street stop cock to the house, which has now been replaced, but it looks like this might have been leaking for a while.

When I lifted the ceramic tiles, a large area had water droplets and appears to be quite damp in places on top of the remaining adhesive. When I tried to remove the adhesive from the top of the quarry tiles, some of them started to sink slightly. We were warned that the quarry tiles may have only been laid on an "ash" layer, but it looks like a relatively soft screed of some type.

I know it's difficult to give a definitive answer on a forum, but any advice would be welcome. We want to level the floor for new tiles, but obviously want to sort out any damp proofing first.

Can anyone provide some help or advice please? Thanks in advance.

I would remove everything that is loose/blown/friable until left with a sound background. Then, dependent on what that background is, and how deep, would prime or seal with appropriate product and bring back to level with screed or self levelling compound.

To get a damp proof floor you will have to dig out and lay a membrane, insulation and a concrete slab floor. Examine all your walls for damp signs and be aware that a membrane can sometimes send the damp up the walls.
Do you mean you now have a new plastic water supply and the lead pipe has been abandoned?
Is the outside ground level below the inside floor level?

Hi

Yes the lead has been disconnected, drained and abandoned. We had a new plastic pipe installed by a company that used an impact mole. The outside ground is below the inside level, and the walls appear to be dry.

Most of the floor is fine, it's just an area that spreads out from where the original lead pipe was and the tiles that move/sink when I try to clean them are the ones nearest the old piping.

If I get someone in for an opinion, which trade would be the best to ask (builder, surveyor etc.)?

Thanks again.

If you've dealt with the source of the water ingress i.e lead main then a patch repair once it's dried out should work, although, obviously, I can't "see" the job from here! You should try and sever the old pipe where it enters the house though, as this could allow groundwater to be drawn in from outside through siphoning/draining/capillary action. As I mentioned, remove all contaminated material and see if the area starts to dry out... A dehumidifier might be a good call! Then you can get an idea of the necessary repairs!

Photos would be useful!

Get the opinion of a tile floor layer ref the background suitability, would they be happy to tile on it if the damp area was patched? Some will be up for tackling the patching work others will only tile on a more or less sound surface.
If the tiler wont make it good then get a general local builder in to have a look.