Dark patches on wall

[andderson365]

Hi,

Moved into house in July and decorated.

Today came in to find dark patches to wall. They don't feel same but we have condensation so wondered if this could be a moisture issue.

If it is condensation and moisture related, would upgrading wooden single glazing to vented UPVC double glazing and adding some air bricks to external walls help?

[GALLERY=media, 85817][/GALLERY]

[GALLERY=media, 85817][/GALLERY]

[GALLERY=media, 85818][/GALLERY]

 

[misterhelpful]

It looks as though they are the patches of adhesive showing through dot and dabbed plasterboard. This happens when they are fixed to exterior/cold walls and the weather becomes colder and wetter. It's something I've seen a lot of in the past where homeowners have covered up cold/damp problem walls to get a quick sale. There's nothing wrong with dot and dabbing but, when attached to this type of wall, I believe an insulated plasterboard suitable for dot and dabbing should be used in order to avoid this issue. (Plastering Forum will be able to confirm whether that is right or not.)

I don't think it's an internal moisture issue, as such, but more of a cold/damp exterior wall in damp weather that is the main problem. That said, any internal moisture issue is likely to factor into the situation, and will eventually form mould spots on those patches, so anything to improve ventilation will help. If you get condensation on your windows or heat loss through them, then considering double glazing wouldn't be a bad idea either, although not essential as even vented double glazing can sometimes restrict good airflow.

 

[Robbie uk]

How old is the house ? Misterhelpful is correct. Some times with old 9" walls you can get penetrative damp coming through which shows up where the dot and dab adhesive is .

 

[JohnD]

Today came in to find dark patches to wall. They don't feel same but we have condensation so wondered if this could be a moisture issue.

//www.diynot.com/wiki/Building:Condensation-in-Houses