Mystery musty smell

[BlueChampagne]

Moved in Sept and the loft conversion in the new house, which is our bedroom, has a musty smell when the windows are kept closed. The house is an '80s build, with the loft conversion in last couple of years. My first thought was cigarette smoke (though I don't know if the previous occupants smoked) but FIL suggested damp, which has got us worried.

Have treated with neutrogena carpet deodoriser and it seems better. Cannot see any evidence of damp except a mark on the stair carpet and small stain on the ceiling beneath, which I assume was a one-off incident.

Any advice or ideas?

how good was the quality of the loft conversion? Do you think it meets modern building regulations?

if there is a leak in the roof, there may be damp and rot in unseen timbers. This will usually be more noticable in warm rainy weather.

Another very common cause of damp in lofts is from condensation. Water vapour is lighter than air, so if anyone drapes wet washing around the house, or on radiators (this is the main cause of damp in UK houses) the moisture will rise until it finds a cold or impervious surface, such as roofing felt.

It meets building regs because it was only done a couple of years ago. And while I do hang washing on the radiators, the smell was around earlier in the autumn when it was going on the line.

We're in East Anglia so haven't had any rain to speak of for ages!

can you get into loft-space which is not part of the converted room? e.g.towards the eaves? see if it smells worse through there?

I am thinking about damp smells, hopefully not dead wildlife.

If you touch the stains you mention, do they feel cold or damp?

We had same thing, turned out it was damp. I bought a damp meter thing off amazon - you stick the prongs in the wall and the reading tells you if there is any dampness. Hope yours isnt that though.

Stains not cold or damp but will sniff-check eaves cupboards. So far carpet deodoriser improvement still holding.