Damp on living room wall & under carpet/underlay

[ASR]

I noticed a small damp/mouldy area just above the skirting in the living room, and having pulled up the carpet & underlay there are a few (relatively small) damp spots that run along the seems of the chipboard floorboards. There aren't however, any damp spots under the skirting or next to the wall. The damp patch on the wall is vaguely semi-circular which suggests it originates at ground level. The house is semi detached and it's on the wall that joins onto next doors - and what worries me is that builders have fully refurbished theirs last month (house is empty - nobody has rented yet).

I dried the wallpaper with a fan heater but it seems to have returned to a cold, slightly damp state.

Would this simply be minor condensation (from cooking & washing/drying indoors with no ventilation) ?
Or could any underground pipes/standing water etc have somehow been disrupted by the refurbishment ?
Or is it possible that there is a problem underneath our floorboards ?

I have checked the water meter - the reading didn't alter over the course of an hour which suggests it isn't a major pipe leaking.
I don't know what type of cavity wall it is, the house is about 15 years old and I'm led to believe rising damp doesn't affect newer builds (?).

If anybody could shed any light on this or rule out a few of the potential problems I would be most grateful!!!

 

[mac391]

It could be any of those things you've described.. The damp area on the wall can be a result on condensation but the moisture in the floor joints not. Unless your washing is dripping on to the flloor??

It's worth changing the way you wash/dry clothes to see if there's any improvement and tick that off the list of possibilities.

If there has been a new concrete floor put in next door, it can cause problems in your property. Its unlikely if the property is only 15 yrs old but until you know for sure it's worth asking.

First thing i would do is make an appointment with estate agents to view next door to see what's been done before you start investigating under your own floorboards.

 

[ASR]

Thanks for your info.
The damp patch on the wall & floor returns shortly after drying and if anything may be increasing. I have a builder coming round to see if he can put his finger on the problem.