Penetrating damp, what is the best way to fix it?

Legacy_user

Hello dear forumites.
I seem to have penetrating damp, coming into a ground floor room.
The damp has appeared at the corner of the roomfrom just around the skrting board to about 2ft from the floor level.
I had marked round the stain a couple of months ago and on checking today, I found that it has spread outwards by another few inches.
The wall does not feel actively wet, but there is moisture there.
We had French doors installed in this room a couple of years ago, leading onto wooden deck, that's whyI'm thinking it's penetrating damp rather than rising damp.
Damp course doesn't seem to be breeched, although we may have to lift the decking to be sure.
Another possibility I wonderd about is that the French door seal may have failed.
I would appreciate any ideas on what may have caused this and also how to fix it.
I don't mind a bit of DIY but I do see the value of getting an expert in to fix it properly.
Thanks in advance,
Linda

System

....anyone?????
I 'm still living in hope of someone sharing their expertise :-)

jc808

sounds like rising damp to me

when u say penetrating - from where? is there a leaky drainpipe etc u can see

System

I thought the damp was spreading in from the outside wall, but there isn't any obvious leak or crack in the wall. That's why I was wonderinf if the seal (mastic/ putty) round the French doors had possibly failed in some way.
Would a builder be the best person to fix it?
TIA
Linda

iamcornholio

Can you post a picture - not close up but from a few metres back so the stain can be seen in context of the room.

Also an external view of the wall on the back of the stained area

G_M

fab_n_funky_mum wrote: »

I seem to have penetrating damp, coming into a ground floor room. How do you know? What are the signs/symptoms?

The damp has appeared at the corner of the roomfrom just around the skrting board to about 2ft from the floor level.
I had marked round the stain (ah!) colour? a couple of months ago and on checking today, I found that it has spread outwards by another few inches.
The wall does not feel actively wet,is the wall painted? wallpaper? but there is moisture there. diagnosed by the stain? or a so-called 'damp meter'?
We had French doors installed in this room a couple of years ago, where - in relation to the damp? Adjascent? Opposite?

leading onto wooden deck, that's whyI'm thinking it's penetrating damp rather than rising damp.

Damp course doesn't seem to be breeched, although we may have to lift the decking to be sure. this is the most likely cause, but you clearly need to establish this 1st. If you need to 'lift the decking' to check, this implies the dpc is beneath the decking - so it IS breaching the dpc!
Another possibility I wonderd about is that the French door seal may have failed. Possible but less likely
I would appreciate any ideas on what may have caused this and also how to fix it.
Linda

Rising damp is very rare. Indeed there are claims it does not even exist at all!

Penetrating damp is much more common. The starting point is to inspect outside, at and around the point of internal damp.
Check the gutters above, the down-pipes, and the drains, for leaks/blocks. Do this in the rain!
Check whether the ground outside has been raised (I strongly suspect your new decking!). But raised flower beds, new paths, even heaps of autumn leaves piled up can breach the damp proof course - damp matter/water lying against a wall will in time penetrate.
Check the pointing (cement between bricks).

If the damp is immediately next to the new doors, they may well be the cause, but if there is dry wall between the doors and the damp stain.... well, it ain't rocket science!

How to fix it? Impossible to answer till you know what you are trying to fix!

Two warnings:
1) be wary about reliabilty of damp meters, even when used by professionals
2) be wary of 'free' damp surveys offered by damp specialist companies - their 'surveyor' will actually be a salesman who will recomend..... a damp proof solution provided by the company!