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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Condensation https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1261267498 Message started by Sandy on Dec 20^th, 2009, 12:04am

Title: Condensation
Post by Sandy on Dec 20^th, 2009, 12:04am

Hi all,

Just looking for some thoughts/opinions on the following problem that's recently appeared in parts of my bungalow.

In the last couple of days I've noticed lower parts of the bathroom and today on the bedroom walls, quite large areas of condensation on the insideof the external walls. I'm thinking that this might be to do with the very cold weather that's descended on the UK (cold walls meeting warm air = water droplets/vapour) in the last few days.

However, what's concerning me is that a few days before the cold snap arrived, I started adding some extra mineral glass insulaton in the loft to help with insulation, but only managed to do above the 2 rooms that have now developed condensation. I am confident that I've left enough air space in the loft area to allow an air flow above the insulation as the suppliers guidelines suggest.

I know it's difficult to diagnose without seeing, but just wondered if anyone might be able to give some idea what could be causing this. The condensation has only appeared on the external walls and only to about 2-4' high. Is this likely to be the cold penetrating through to the inner skin of the walls (no Cavity Wall Insulation in the house), or is it likely that the additional insulation has caused a problem? If it is the extreme cold, is it likely that Cavity Wall Insulation would prevent this to an extent next time, and is it something that should fade away once the cold snap ends?

Any ideas, gratefully received. Thanks.

Title: Re: Condensation
Post by CWatters on Dec 20^th, 2009, 9:59am

Won't be the loft insulation.

Would be interesting to measure the temperature of the surface of the walls where they are damp.

Title: Re: Condensation
Post by woodsmith on Dec 20^th, 2009, 3:08pm

This is one problem of adding insulation, if you have a cold spot, like your wall, it will attract more condensation.

Ideally you need to warm the wall by adding insulation, or you could reduce the relative humidity in the room by ventilation or by using a dehumidifier.

Title: Re: Condensation
Post by Sandy on Dec 24^th, 2009, 8:53am

Thanks for the replies. I've been trying to find one of those strip thermometers that I can stick to the wall to get a temperature, but the Christmas "shoppers" are p1ss1ng me off too much to warrant trudging round shops trying to find one.

However, the extreme cold has abated somewhat and the condensation has receded with it, although there is still a fair bit forming at the lower sections of all the DG units.

Reducing the heat inside and opening doors to allow a better airflow seems to have helped aswell (maybe SWMBO will be getting a thick ear, sorry thick jumper for Christmas instead of cranking the heating right up!!).