Dampness/humidity

liam336

My wife and I moved into our new flat a couple of months ago. Before buying, we had an independent damp surveyor come and check things over after a homebuyers survey had reported 'dampness'. The indie recommended the front bay living room wall should have a damp membrane installed and that new subfloor vents should be installed to allow air into underfloor cavaties. After moving, we got the work done and the indie came back and agreed it was done to standard of PCA.

Two months into living here we find the humidity level is quite high (about 70% first thing in the mornings - with windows open it goes down to between 55-65% during the day.) We also find that bedding and other fabrics feel a little moist and are worried that dampness remains. There are also some small patches of mould that appear in the kitchen cupboards and on items pressed against the bedroom walls.

We've been active in trying to get the humidity down: keeping bathroom door shut and extractor fan on for good 20-30 mins after showers (no windows unfortunately), keeping windows open to allow air to circulate, using a reasonable sized dehumidifier when windows are shut, not drying any clothes in the house (we used a condenser tumble-drier), putting lids on stove items. Annoyingly, the kitchen has an extractor that only deals with odours and doesn't remove moisture. We use the dehumidifier during cooking.

I've looked at dozens of different posts where people are in similar situations, but none seem to be quite the same. I'd really appreciate any advice, particularly if people have had similar experiences. I've been thinking a positive input ventilator might be worth exploring, however we have a very limited budget since the move (and a baby on the way this November).

Thanks in advance for any suggestions!

DRP

Did the new ventilation (air bricks presumably?) lower the humidity at all?

Tbf the atmosphere is very humid at the moment- but you shouldn't be seeing mould growth.

As a comparison, today my hygrometer said 68% next to an open window this afternoon - our hallway (known damp problem) said 76% and is consistently 5-10% above atmospheric humidity.

liam336

Thanks for your reply DRP.

They are airbricks. I don't know how much they've lowered it by as only in the past few weeks have I begun measuring the humidity (since the appearance of mould patches.) The air bricks were installed nearly 2 months ago.

When we use the dehumidifier it helps to bring the humidity down to about 60-65%, but no lower. During the day when we're not in, and windows are closed and dehumidifier is off, it can easily rise to 70-75%.

Any advice or suggestions greatly welcomed.

paddyrg

The dehumidifier may not be of the optimal type, or may be too small for the space it's trying to dry.

System

Be careful to leave ventilation space behind furniture so mould is less likely

I think it comes down to cold walls/windows causing condensation, some sort of wall/window heating might help where insulation fails