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Blocked cavity causing damp??

Postby storeyboy » Sun Dec 14, 2008 5:59 pm

Hello all.

I live in a terrace house but the terrace has staggers along it creating exposed corners on some houses (mine). I have a problem with damp in this 'exposed' corner of our bedroom. We try our best to battle the problem but we have no central heating, but storage heaters down stairs and convectors up, plus the windows have no trickle vents or a lockable vent position. We try our best to combat the moisture in the house ie, cook with lids on pans, shut the door while showering etc, and use a dehumidifyer for a few hours in the room most days.

It was suggested that we put a vent in the ceiling through to the soffit board to get some fresh air in that corner. So i popped up my ladder to that corner of the house to have a looky. I had seen birds going in and out of the loft area under the tiles above the guttering and didn't really think TOO much of it (i wasn't happy but figured i'd leave em be)

When i removed some tiles off the corner i came across the biggest nest i have ever seen. It took me all morning to clear and filled a black bin bag full of grass, reeds, sweet rappers, string you name it, the swines stuffed it in there!
Anyway, the nest had totally blocked the top of the cavity in that corner by a good 3 or 4 inches down into it on one face and even further on the other.

Could such a densly packed blockage to the cavityvbe causing our damp problems? And how does it differ to cavity wall insulation? I know cavity insulation materials are treated to prevent damp tracking across the cavity but would it help in that corner.

sorry for the ramble, thanks for any help in advance!
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Simply Build It

Postby stoneyboy » Mon Dec 15, 2008 10:58 am

With cavity walls it is very unlikely that the damp is due to bridging of the cavity unless the birds have dropped so much material down the cavity that it is causing a bridge.
Suggest you get hold of a humidity gauge and thermometer. If you Google "" and view the dew point calculator this will give you the dewpoint. Measure the temperature of the wall where the damp is and if the wall temperature is below dewpoint, condensation is the most likely problem.
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Postby storeyboy » Mon Dec 15, 2008 9:21 pm

thanks for the reply stoneboy. I didn't steal your alias name by the way, i always use storeyboy as my alias as it was my knickname at school. Anyway, back to topic!

The nest was obviously years of hard work. It had totally blocked the cavity from the top of the walls down about 8-10 inches in places! Some of it is still in there, its too far down the cavity to reach.

Thanks for your help with determining the problem. I will try your suggestion and see how i get on.
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Postby TheDoctor5 » Fri Jan 30, 2009 9:54 am

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