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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> New flat appears to have a damp problem? https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1371825305 Message started by jazzyman on Jun 21^st, 2013, 3:35pm

Title: New flat appears to have a damp problem?
Post by jazzyman on Jun 21^st, 2013, 3:35pm

I recently moved into a downstairs flat and I am concerned that there may be a damp problem in the property.

First noticed that there was a problem with the bedclothes feeling damp all of the time (never happened in the old property) my wife is also saying that the floor rugs also feel damp. We leave the windows open quite a bit through the day, so I cannot see that it may be a ventilation problem. The exterior walls also feels as though they are damp. Checked with a hygrometer and the bedroom is around 68-70%, is that ok or is there a problem?

Title: Re: New flat appears to have a damp problem?
Post by woodsmith on Jun 22^nd, 2013, 8:55am

By downstairs do you mean in a basement? We had a basement room at our previous house and that could feel damp in the summer as the room walls and floor are relatively cool and the warm outside air is relatively humid causing condensation to form on everything in the room. Opening windows made it worse as we were drawing more warm humid air into the room. We bought a dehumidifier which we just ran when the weather was warm which helped a lot. The problem disappeared in the winter. In the end we insulated the floor which raised the base temperature which cured the problem.

Title: Re: New flat appears to have a damp problem?
Post by jazzyman on Jun 22^nd, 2013, 9:27am

It's not a basement apartment but a ground floor, floors are therefore concrete. I was considering getting a dehumidifier but thought that if there is a damp problem I will just be masking things.

Regarding the hygrometer reading which appears to have now settled down to 68% does this reading prove anything?

Title: Re: New flat appears to have a damp problem?
Post by woodsmith on Jun 22^nd, 2013, 11:07am

Probably not, I'm up in Shropshire and the humidity in my workshop, which is more or less the same as outside at this time of year, is 68% today.

But it all depends how cold the walls and floors are as to whether you get condensation or not,

As a cheap but effective test, you could try putting some plastic on the walls or floor; it needs to be firmly pressed down so that no air can get underneath. Leave it a day or so and see if water has formed on top or underneath. If its on top you have condensation if underneath you have damp.

Title: Re: New flat appears to have a damp problem?
Post by cumbriahandyman on Jun 22^nd, 2013, 4:42pm

What sort of ventilation do you have in the property?

http://www.handyman-cumbria.com/Pages/Condensation.aspx

Title: Re: New flat appears to have a damp problem?
Post by jazzyman on Jun 23^rd, 2013, 8:12am

There is an extractor fan in the kitchen (automatic type) and a manual extractor fan in the bathroom. We also leave the windows open weather permitting.
The strange thing is that we do not get any condensation on the windows, which I thought would happen if there was a condensation problem?

The ground outside is very water logged due to the property being built at the bottom of a woody mountain, so perhaps this is the cause?

Title: Re: New flat appears to have a damp problem?
Post by woodsmith on Jun 23^rd, 2013, 11:52am

Condensation forms on the coldest surface, if you have relatively cold walls and floors you will not get condensation on the windows.

If you have rising damp it normally comes up the wall to the height of about one metre and you often see a distinct line on the walls at this point.

Try the plastic test, you can even use a plastic carrier bag, and report back.