Internal Damp Help

bournegardens

I have recently redecorated the living room as there was pretty bad damp blistering one of the external walls. I took back the old plaster to the brick and gave it chance to dry out before re-plastering. I checked the guttering and the external wet dashing. All seemed ok, maybe a coat of paint needed. Nothing much, all mastic round window is good too as recently replaced.

After one month (and some bad weather) the damp has come back even wrose, not up from ground level but in the middle of the walls. It is already blistering the new paint and I was wondering if anyone had any advice as to what I can do or try?

Thanks

Hermanmunster_2

Are you sure it isn’t internal condensation forming with cold walls and moist air in the room condensing onto them?

bournegardens

Yeah because it is in different patches on the wall. Its coming in somehow. Its driving me mad, especially after I have just painted the room!

Thanks for your reply

David_Aldred

Hi,
A wet external wall would take several months to dry down once the moisture problem was resolved and not just one month I am afraid. However could you please tell us how old the house is, whether the external wall in question is a cavity wall or solid wall, if it is cavity wall is the cavbity insulated, is there a damp proof course and what type of plaster have you used in making good? In addition what colour is the mortar of the brickwork in the area you re-plastered - i.e. creamy white or a dark grey with black bits in? Kindest regards, David

bournegardens

Hello,

I have a feeling that the damp problem is not resolved. The house was built in 1901 and to be honest I am not certain whether it is a solid or cavity wall. I was wondering whether to take out a brick on the inside to see this. I would do the outside but it is rendered down to the ground - which may have something to do with the problem?

I cant see the damp proof course as if it is there it has been rendered over?I have no idea how I would go about putting in a damp course if I need to.

The mortar between bricks when I plastered was quite crumbly, mostly still a bit damp. I used bonding then multi finish to patch in on the inside.

Thanks for your reply,

David_Aldred

Hi, The bonding plaster in particular is unsuitable for application to walls troubled with dampness as it will tend to act like a sponge pulling moisture from wherever it can including from the air within the room itself, such that even if you have resolved say an issue of penetrating damp the plaster may not dry down when of this type. Given that you are unsure of things it may be prudent to have somebody qualified from the property Care Association (PCA) inspect and advise you about what they can see is going on rather than you start pulling the wall apart. A list of both PCA member contractors or if you prefer somebody independent (Freelance or Consultant) may be found upon the PCA website (google Property Care Association) for you to choose somebody close to you to inspect. Kindest regards, David

bournegardens

Thank you so much for your help. I will do just that.
Kind Regards,

Gary