Bathroom lower wall damp

[maria_6]

We moved into our property in January and have been having some damp issues with our downstairs bathroom which has been built as an extension.



It’s primarily on the lower part of the wall, going up to about mid toilet (behind which is the garden), and there is visible bubbling of paint and damage to the skirting.



The room is kept well ventilated and we have a dehumidifier. We’ve compared photos to April and the damage does look to be getting worse.



We’ve found out that one of the previous owners bricked up the area which meets the wall just before they sold. Our neighbours who were friendly with these specific owners and visited our property often confirmed that they never saw any signs of damp. Prior to this there was decking and our neighbours think it may be the bricked up area is causing rainwater to collect.

Prior to this, the steps in the final picture went all the way across and the now bricked up area was level with the bathroom floor.


We’d really appreciate any thoughts on how to proceed or if there are any other opinions of the cause. At the time of our survey nothing was flagged in regards to the bathroom/this wall.

 

[Cubist]

If the patio is immediately outside the bathroom and its surface is higher than the bathroom floor indoors then that is the cause of the damp indoors. Can you confirm?

 

[maria_6]

If the patio is immediately outside the bathroom and its surface is higher than the bathroom floor indoors then that is the cause of the damp indoors. Can you confirm?

Yes thats right

 

[Cubist]

Sadly that patio, or at least part of it, needs to come out. It has perhaps bridged any damp cause in the wall of the house and this is allowing water to penetrate the wall to appear indoors. Take a look in the Projects section here at the Topic 'Zebcolm Trench' or others here concerning French Drains.

 

[a twig]

Thread 'The Zebcolm Trench'

Oct 10, 2022

The Zebcolm trench is so named because I made one, and then malcolm made one. If you make one, let us know and we can elongate the name.

The Problem: ground levels higher on the outside than inside, causing penetrating damp through solid wall, with no possibility of lowering external ground levels.



The Solution: a trench with a retaining wall, topped by mesh grid, which allows air to circulate beside the lower portion of the wall.

First you dig - the rule of thumb is that you can dig to the bottom of the last foundation course. If you need to , you can then dig down away...

• Zebra
• Replies: 40
• Forum: Projects

• 

 

[Flyfisher]

I agree that the patio is a prime suspect, though being a bathroom I'd also want to satisfy myself that none of the pipework or sanitaryware is leaking. Even a tiny leak slowly dripping over a period of time will deposit a lot of water where it shouldn't be.