Help! Why does my house smell damp 😩

[yoursweetpotatoesarebland]

Please be kind because I’m trying not to panic too much! I bought an old cottage about 6 months ago. It smells damp and I don’t know why.

It’s solid stone I think. Downstairs there’s a small single story extension which is unheated but has a vent and is my utility. I have a dehumidifier in there, it is damper than the rest of the house and hovers at about 50%. It has a door to it that separates it off from the main house which is almost always closed.
the rest of the house doesn’t show as damp on the dehumidifier- 40 max. But when I get back it smells damp and the other day I took a change of clothes out of my bag at a friends house and they smelled musty too. There’s no mould or damp patches anywhere or anything.

please help I am so worried that I’ve bought a house with a damp problem and I don’t know what to do about it!

Are you heating the house enough ?
How are you drying clothes, as a tumble dryer is really vital in a damp house.
Do you open windows every day ?

Could you try putting a heater in the unheated bit? That should dry it out a bit

Yes have a tumble dryer and don’t really dry washing inside - the odd wool jumper or delicate item but the dehumidifier is on all the time.

it’s pretty well heated - set to 18 and sometimes give it a boost. I’d have to put a portable heater in the utility and I think that might cost an absolute fortune to run.. I guess I could keep the door open though? I dont open windows every day in the winter… but I do in spring / summer etc. it’s freezing 😬 do you think that could make a difference?

Old houses need airing. Open the windows every morning, even just for 10 minutes or so, however cold it is. I would probably open the door to the utility when I went up to bed to let some of the warmer air in the house into it and see how that goes.

If the utility isn't heated then all the moisture in the air in the rest of the house will just condense when it gets into the pantry. You could try leaving the door open all the time or try a small oil filled radiator. Is there a way you could get an extra radiator plumbed into the utility?

Yes.. I assume that’s why it’s damper than the rest of the house. It’s also single story and a relatively modern extension to a very old house with enormously thick walls so none of the heat really transfers either.

would having one damp room at the side make the whole house smell damp though? It could be me being naive but I assumed as the door was shut it wouldn’t ”spread” so to speak?

It could do if the damp is ingrained and starting to break down whatever is in that room. Like kitchen cabinets etc.

There is nothing in there except for what I added really recently - washing machine, dryer etc. it was literally a concrete shell when I bought it and I added flooring plumbing electric etc to make it usable

Did you damp proof and insulate it?

If there isn't a damp Proof in the floor then the floor covering could be trapping moisture in and that could be what the smell is.

Sorry - I should have been clear. The walls were freshly plastered and concrete floor laid - I didn’t build it. It’s a relatively modern extension and has building regs sign off but the previous owners didn’t use it for some reason 🤷🏻‍♀️

Did you smell the damp when you viewed the property? Did you have surveys/checks completed on it?

Yes had the top available survey- it pointed out the utility was a bit damp on the meter but that it was unheated with no ventilation so this wasn’t surprising. I then had the whole property checked out by a builder who said this was the case and there were no underlying issues with damp causing it.
But it didn’t smell damp then and I’ve taken actions which I thought would alleviate it and it now smells damp!

Problems with the floor? Rising damp?

I've lived in old houses for most of my life. Sounds like the damp-proof course has failed. This can happen when electric sockets have been put in too low or unsympathetic skirting boards are put in puncturing the course & allowing damp to rise up-it's easy to do. I suggest that you get a several experts in to give a look to get a consensus of opinion. In the meantime a dehumidifier should help as well as PP's suggestion of opening windows for 10 minutes everyday (which is something I do as a matter of course) but I'm a fresh air freak & open windows in every room every day. LOL!

It's quite easy to get rid of the smell & signs of damp temporarily when selling a property. No heating, no ventilation is a recipe for damp problems.

A new extension should not be damp if it is reasonably ventilated and heated.

Look for sources of water such as a leak. Possibly rain at a window, possibly a sink or pipe.

The concrete floor should be dry, even if you put a plastic mat on it which prevents evaporation.

Look at the walls around skirting level.

Look at the outside for damp patches caused by faulty drains or leaking gutters.

Do not allow anyone who sells silicone injections into your house, even if they call themselves a damp consultant.

There's a website called Heritage House which has lots of info on damp in old houses, may be worth a look.

Thanks to people on here I recently paid for a damp and mould survey. It was worth every penny. ( £500). I was about to waste a lot of money on what I assumed would be the source of a mould problem but they identified the correct source and how to rectify it.

I would definitely recommend you do the same before you shell out any more £££

50% is not high humidity.

When you say "freshly plastered and painted" who did that ?

Do you have a contact for whoever you dealt with? This is definitely something I would consider.

It’s stressful not knowing what the right person is to help as there is a lot of conflicting info online about damp issues.

There was a leaking gutter at the side of the house earlier in the winter - now repaired. There are no damp patches outside now and having checked there is no evidence of any issues around the skirting boards except for one small bubble behind a radiator in the kitchen. The floor is a little bit uneven in one place - its not very new laminate boards. I kind of assumed this was just par for the course..
I wondered about the damp proof course - there are some flower beds outside and the garden is on a slope meaning they actually come quite high up the wall… i wondered if that might be causing an issue? There’s no obvious issue near that wall though and it’s the opposite side of the house to the damp utility….

thanks so so much for the comments - i really appreciate the help 🙏

Could they be blocking air bricks?

Without heating the utility, you won't be able to tell easily if the damp smell is because of condensation or if there is another source of damp. If you can't see any damp it must be under the flooring or behind one of the appliances? Could the washing machine be leaking?

Old stone houses need to breathe. And any modern day updating needs to take account of that. Even using the wrong paint in walls can seal in damp and causes issues. When you say newly plastered and rendered do you mean since you moved in? Or before? Either way, using what materials? Therein may lay the answer. I’ve got a very old stone houses, no foundations. Has to be treated very carefully even when just cosmetically decorating.