DIY Doctor

Main navigation

Specs of condensation/damp on external facing wall

Postby rightnow » Tue May 19, 2009 7:54 pm

Hi Stoneyboy + others,

I own a first floor flat which has a pretty big problem with air circulation and condensation and has the full 5 years I've lived here. I've muddled by without any dramatic side effects until noticing in the past 3 months little circles of moisture appearing on an exterior facing wall in the bedroom which has the biggest condensation issues.

I've had a builder out to take a look and I'm waiting for him to report back to my factors on the likelihood of damp rather than just a visible affect of the condensation but in the meantime bought a dehumidifier to help with always present condensation issue.

I was just wondering how long the dehumidifier would take to have an effect? and would it likely cause the specs to dry out (assuming its the condensation causing them) or should I be putting up lining paint and doing a spot of redecorating.

thanks for the help, really nice website.

Rank: Labourer
Progress to next rank:
Posts: 2
Joined: Tue May 19, 2009 7:50 pm


Simply Build It

Postby Perry525 » Wed May 20, 2009 6:00 pm

Condensation results from water vapour and cold.
The water vapour you put into the building, the cold is, well due to lack of heat.
Water vapour comes from washing, cooking any use of hot water.
The water vapour hangs in the air until it finds a cold spot on which to condense. Usually a cold window. Often a cold wall.
The solution, use an extractor fan in the kitchen when cooking and in the bathroom when washing. Keep the doors to these rooms closed.
Keep the rooms warm, or open the windows and keep them cold.
Rank: Site Agent
Progress to next rank:
Posts: 734
Joined: Fri Jul 06, 2007 7:35 pm

Postby bd3cc » Wed May 20, 2009 9:02 pm

On a 1st floor flat, IMHO likely to be condensation rather than penetrating.
See how much water the dehumidifier takes in, in a day. It will take current moisture out of the air, but will not cure the black spot problem, as this is a fungus, and needs treating seperately. Neat blech may do this, but you will need some redecoration afterwards.
Do you have any form of extractor to the o/s?
Do you use a tumble dryer
Or have you recently started using a shower more?
All of these can cause a problem.
Rank: Foreman
Progress to next rank:
Posts: 323
Joined: Wed Jan 30, 2008 8:02 pm

Postby rightnow » Thu May 21, 2009 5:01 pm

Thanks for the replies folks - yes we have both a tumble dryer and a shower with extractor fan so will make sure that's on when in use and the doors shut and window open when using the dryer. The dehumidifier has been pulling lots of water out of the air so will keep using it.

Also will give bleach a try on the specs the room is due redecorating anyway.

Again - much appreciated to those in the know who offer the rest of us the advice!!
Rank: Labourer
Progress to next rank:
Posts: 2
Joined: Tue May 19, 2009 7:50 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