Water damage to wall plaster after underfloor pipe leak: next steps

21 Oct 2011
Reaction score
United Kingdom

I have had a water leak under my tiled concrete kitchen floor but (I think) above the DPC- a mains water copper pipe with a pinhole in it had been leaking, we don’t know how long for. We noticed the leak when water began seeping out of the gap between door frame and floor in the room next to the kitchen. It’s possible this was going for a while and a lot of water leaked out, but we can’t be sure.

The leak has been stopped and I have a shiny new trench in my kitchen floor. Plumber is going to upgrade the pipes and make everything water regs compliant.

Two days after stopping the leak (yesterday), water damage began to appear in several of my walls, in a 4-5 meter radius from the the source of the leak. I think the walls are ordinary gypsum plaster. At the moment, it’s not too bad, and some of it is quite minor. For now there are 5 problem spots, and the rest of the walls are fine. In a few spots, though, the paint has bubbled and flaked off, and there is salt on the wall. It goes from between 5cm to 14cm up from my skirting board, and runs along in 30cm lengths. In one place, the plaster might be blown. Photos in post below.

I’m not sure what to do next. I guess I need to wait for a while to see whether the existing spots get worse (I don’t know how much water is under the floor), or new spots appear. A dehumidifier is arriving today.

Any ideas as to when I can start feeling confident no new damage will appear?

Once it’s all settled (any ideas on how long to leave it all?), what should I do next? Can I treat the plaster with a salt retardant and paint? Or stain blocker (like damp seal) and paint? Or both? Or should I be looking at removing the damaged plaster? Or more than the damaged plaster?

Any advice on what I can expect to happen and on what to do next would be greatly appreciated. Many Thanks.
Last edited:
Sponsored Links
134CEB63-DE63-4255-B6C9-8ADFF11F5BA8.jpeg 74B138D4-8585-4E34-8227-6B2036BD784A.jpeg 48FF8697-B541-4C87-B2DD-170CC0D41042.jpeg 97043594-44FE-47B4-9739-0F411C45D979.jpeg FBFDDC16-591F-43E9-898D-B5AC39E6E3B0.jpeg

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links