condensation problem

27 Apr 2011
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United Kingdom
I live in a 1960's council bungalow, having loft and cavity wall insulation. It's double glazed and has trickle vents that I leave open all year.
I have and use centrifugal extractors in the kitchen and bathroom and leave them running for quite a while.
Two of us live in the house and each have a bath daily leaving the window open or at least the fan on for quite some time, I try to dry wet towels outside, weather permitting.
I open all the windows as often as possibe, even giving the place a "quick airing" on cold days.
I dry washing outside, rarely use my dryer (condenser type) and then I open the back door next to the dryer.
I tend to leave all internal doors open at night.
On a cold morning every window is running with condensation and on a cold damp night even the wooden parts on the external doors is running with candensation.
last night it was cold and very damp outside and all my windows and doors were bad in some places it had run onto my carpets and wet them.
On my weather station this AM it read humidity out 80% Inside 70%
I have tried all the advice and tips I can possibly do the only thing I have not yet tried is a dehumidifier, would this help?
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try keeping the internal doors shut and see which rooms suffer most

How do you heat your home? What is the internal temperature?

you get a lot of condensation even in rooms where the trickle vents are open?

Try to look under the floor and see if that's wet. Look at your airbricks that ventilate the subfloor and verify there are all clear of cobwebs and rubble and there should be a slight draught through them from one side of the house to the other, that will show by blowing cigarette smoke.

It is possible you have a water leak, maybe round a radiator or under the floor, maybe in the bathroom.

As an experiment, shut the internal doors and leave the bathroom fan running overnight. See what difference that makes.

Look in the loft and see if that is wet.
Thanks for your reply,
I have tried closing the internal doors and each room suffers the same, can't leave doors closed at night as have a dog who likes to roam about.

I heat the house with gas central heating.
The external airbricks are sealed I assume when the cavity wall insulation was done as they are above the DPC.
The floors are concrete and are dry where I have lifted the carpet.
Also I have checked the heating pipes and all are dry, no leaks.
The loft is also nice and dry.
I get the same problem, also in a bungalow with concrete floors.

I get black mould behind cupboards and headboard. It got so bad that it was wet under the carpet at one gable end of the house.

I bought a huge B&Q own brand dehumidifier and it does help a lot, but the problems come back when I don't use it.

When I bought the house, the surveyor said that an air-brick should be put in the roof in a gable end so I'm wondering if that would help solve the problem.
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What about heating use patterns and temperature - possibly high temperatures for limited periods of time allowing air to condense more often?

Also close doors to kitchen and bathroom where possible

It may be that the property is particularly susceptible to condensation so a dehumidifier or positive pressure fan would help - see the "lofty " thread in the building forum

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