Another Damp Window query- insulation??

JulesH · Post by **JulesH** » Fri Dec 04, 2009 5:02 pm

Hi,

Our bedroom window (in top floor flat) has quite bad black mould in the 2 bottom corners on the adjacent walls (window is part of a gable- so sits out from the exterior wall like a small square bay window- if that makes sense?!)
There are 2 other windows like this in our flat which haven't suffered any mould, however I wonder if the bedroom is suffering because we have the window open all spring/ summer, so maybe the rubber seal has been affected by being exposed to the elements over the last few years?
Also we have had roof leaks in the same area- which I don't think are directly related, but we have pulled back the insulation to allow plasterboard in the loft to dry, so the room feels colder overall. Could this be causing more condensation to form when we've had the heating on in winter and shut the curtains. The room feels alot cooler than all other parts of the flat.
I suppose the silicon sealant could be replaced also- should this be done on the inside and outside of the d. glazing?)

It still doesn't fully explain the draftiness in the room though?

Thanks

python · Post by **python** » Fri Dec 04, 2009 7:43 pm

Pics would be a big help.

You likely have failed lead flashings or some similar problem on the outside.

gib_goblin · Post by **gib_goblin** » Sat Dec 05, 2009 12:27 am

I can tell you from personal experiance, a leaky roof can lead to damp problems in places you wouldn't expect.

We've just had our leaky roof fixed (cheers Python

), the water was finding its way into the loft, then down the inside of the walls and being soaked up by plaster.

If you have pulled back the insulation and you're only heating the room for part of the day then you will have a big temperature variation which will cause condensation on cold surfaces (Windows). This wouldn't explain the wet plasterboard in the loft! That is bound to be a leak of some kind.

JulesH · Post by **JulesH** » Sat Dec 05, 2009 9:49 pm

Thanks for replying folks....

We have had bad leaks in all 4 of our exterior rooms to some extent (for the last 6-7yrs- it been a long saga but we're hopefully due a new roof!) The other 2 rooms with the same bay windows don't have any form of mould next to the frames and 1 of them has had water consistently running under the plaster whenever its rained heavily for several yrs and is also barely heated as its the spare room and we spend no time in it. Although I suppose we don't lie breathing in there all night like in the main bedroom- which will make condensation worse?

I can't get access to the outside of the window safely as we're 4 floors up but I will try to post a pic of the inside. I think the mould is definitely more related to poor seals/ temp and condensation than the roof leaks as it seems to stop growing during summer when window is open (regardless of rainfall) and re-occurs in winter. Also any leaks under the plaster in main bdrm are at the front edges of the bay window walls (into the room) and the mould is in very precisely located round patches right next to the window within 15cm height of the windowsill....
any other ideas? Ta

JulesH · Post by **JulesH** » Mon Dec 07, 2009 1:00 pm

anyone- any more suggestions??

Please :(