DIY Doctor

Main navigation

Damp Ground Under Floorboards Causing Damp on Interior Walls?

Postby mark2422 » Tue Aug 02, 2016 12:20 pm

Hi, since moving into our house 18 months ago we have noticed damp at the bottom of the 3 interior walls under the stairs. The damp shows through on the other side of the walls in the dinning room and front room.

This morning I decided to take of the skirting boards and lift the floors boards to see if it was a leak on a radiator pipe as all 3 walls each have a radiator on them and the pipes go under the floor.

I did not find any leaks on the pipes as all the insulation around them seems pretty dry, but the ground under the floor boards is very damp. It does not seem to damp on the opposite side of the room next to the exterior wall.

I will upload pictures. Any advice as to what might be the cause of this and what (if anything) can be done without spending thousands of pounds?


Pictures -
Rank: Labourer
Progress to next rank:
Posts: 2
Joined: Tue Aug 02, 2016 12:06 pm


Simply Build It

Postby welsh brickie » Tue Aug 02, 2016 7:33 pm

unfortunately the floor area is so shallow that air cannot circulate, to dry out any moisture.
It would be best to remove all the wood flooring, insulate, add a damp proof membrane and concrete. It will not improve unless that method is implemented
welsh brickie
Rank: Project Manager
Posts: 2611
Joined: Sat Apr 12, 2008 7:54 am

Postby mark2422 » Tue Aug 02, 2016 11:41 pm

Thanks for the reply
Rank: Labourer
Progress to next rank:
Posts: 2
Joined: Tue Aug 02, 2016 12:06 pm

Postby Paul1847 » Fri Sep 02, 2016 11:32 am

A few years ago we did exactly as Welsh brickie suggested to deal with standing water under floorboards (work done by reputable builder). Very satisfied, but hoping you could advise with issue around chimney breast. (We've been putting off dealing with it!) Seems obviously damp and it has been spreading, with salts blowing the plaster in places. Wondering if concrete has bridged the damp course in the chimney breast foundation?
Can I solve this relatively easily?

Pictures linked below.
many thanks
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Fri Sep 02, 2016 11:05 am

Postby Mr Len » Tue Sep 06, 2016 9:29 pm

Hi, i have an almost identical issue. Internal walls with damp showing at a consistent level.

Pictures uploaded here ... %20Uploads

Any hints or tips are hugely appreciated!!

All external walls are fine as is the area under the boards away from walls.

What do i need to do to get rid?

Mr Len
Rank: Apprentice
Progress to next rank:
Posts: 7
Joined: Sat Jul 16, 2016 7:58 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