DIY Doctor

Main navigation

Inexplicable water leaking and penetrating damp

Postby leonardleonard » Mon Jan 10, 2022 6:59 pm


I have penetrating damp in my bathroom on the walls and on the ceiling.

On investigating (i.e. removing some tiling to see behind the bath) the inside wall is soaking wet, and there is a constant drip of water from water running down the inside walls/timber.

On investigating the outside of the wall, there is a constant stream of water coming out cracks on the outside of the wall.

I have had two plumbers come out and look at this. Both are telling me - nothing is leaking. They checked the flat above and removed her bath to look under it, but the floor under her bath is totally dry. They said they checked all the piping in my and her bathroom and nothing is leaking. Yet, inexplicably, apparently between the bathroom floor of the flat above and the ceiling of my bathroom, copious amounts of water is appearing.

The two plumbers that came said they thought the source was poor brickwork on the outside of the building, meaning that when it rains water is absorbed in like a sponge, this is then pooling between the floors, and slowly seeping through.

I find this explanation very hard to believe - A) I would expect it to get worse when it rained and slowly improve over time, it does not (the dripping is constant) B) water streaming out of cracks in a wall suggests to me the water has an inside source, rather than an outside source.

Is there explanation reasonable? Could there be something else going on here? I really don't want to have yet another plumber come out to look at this but at the same time I can't imagine waterproofing the outside brickwork is really going to stop this leak.

Thanks a lot
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Mon Jan 10, 2022 6:48 pm


Simply Build It

Postby stoneyboy » Tue Jan 11, 2022 11:18 pm

Hi leonardleonard,
I would agree that it must be more the rainwater ingress.
Turn off your mains stopcock with everything else in the house off. If the mains pressure drops you have a mains leak. If you have cold water tanks have a look at them and see if water is constantly feeding into them.
Regards S
Rank: Project Manager
Posts: 5084
Joined: Wed Dec 10, 2008 6:44 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics