Help me identify new musty smell

[SE13Mummy]

Over the past three weeks a new musty smell has been noticeable in specific areas on the ground floor of my house. I first noticed it after days on end of heavy rain and hailstones. I could smell it when I entered the house and it only seemed to affect the bit of hall near the front door. Running the dehumidifier has improved it and on hot, dry days when there's someone at home the downstairs windows have been open all day which has reduced the smell without need for the dehumidifier. Yesterday I realised the musty smell was near the cupboard under the stairs so moved the dehumidifier. This morning DH said he could smell the musty smell from upstairs so put the dehumidifier on during the day.

I've had a good look around for anything that might be damp but there's nothing obvious. The air bricks at the front of the house seem to be clear and there's no damp/musty smell coming from them that I can tell. The house is a mid-terrace, 115 years old and near the top of a hill (of London clay). Window frames are wooden throughout and the glass is not double-glazed - they've been completely overhauled and refurbished over the twenty years we've been here. There doesn't appear to be any leaking from the guttering, the downpipe at the front of the house feeds into a water butt and that all seems to be fine. We don't have any pets that might be responsible for bringing in dead animals and we don't have a cellar/basement.

So, what else can I check? The washing machine sometimes smells a bit but the door opens the 'wrong' way so it's difficult to keep it open all the time if the utility door needs to open. I've always tried to keep the washing machine door open as much as possible. About the same time as the musty smell started DH bought a box of green tablets that are meant to clean the washing machine. We've used one about once or twice per week since then but nothing else has changed. In case it's relevant, the utility room floor is stone and there's a shower and loo in there too.

Please send me your ideas of what I should be looking for, and where.

It could be a drain problem. Drains nearby may be leaking under your home.

I'd call the water company...or whoever is in charge of the drainage in the street.

It could be mice? Have a close look around for droppings. Mice tend to wee everywhere which can smell musty

I would say it’s mice or a rat but I would go with mice .

I had this once, the smell seemed to move around the house, it was so bizarre. It took me ages to realise it was OH's slippers!

Possibly a dead mouse under the floorboards? I can never work out why something as small as a mouse can smell so much.

It could take a couple of weeks for the smell to disappear if it is a mouse.

@itstheyearzero

I had this once, the smell seemed to move around the house, it was so bizarre. It took me ages to realise it was OH's slippers!

I have suggested to DH it may be his slippers but he thinks not. Perhaps I'll put all his footwear on the washing line and see if that solves the problem!

I was going to say mouse too. They really stink as they decompose especially in this hot weather. Give it a few weeks and it will go as it rots away. Or you could pull up the floor boards.

Drains will have a different smell. A sort of sickly smell rather than musty.

Windows open for a good few hours will help

Washing machine run on a Hot hot wash while empty

Run a blast of water down all your drains bathroom and kitchen for 10 mins straight each day - I had a plumber tell me to do this regularly to minimise blockages anyhow

Is the smell in the air or along walls or in the floor (you may need to literally sniff your floor and walls to check!)

Yankee candle is your friend otherwise

Do you ever use the shower and loo in the utility room? I've heard before that when the shower for e.g. isn't ran/used, the pipes/drain dries out and a pong could emanate from there.

Otherwise, when the washing machine operates, is there any unusual gurgling in the sink?

I just found a dead mouse drowned in a pool of water in my son's tractor trailer he keeps by the backdoor. It was disgusting. But as we are just about to do a house viewing I'm glad I spotted not the viewers!

Is it wrong to hope it's a decomposing mouse...?

The smell is definitely in the air rather than on anything solid such as walls, floors, furniture - we've done lots of sniffing! The shower and loo in the utility room get used daily so I would be surprised if they're the culprit.

I thought the cat had pissed in a few of our rooms, nope, it was my husbands sweaty cycling clothes/ shoes........

Could it be that?

Another vote for a mouse. We had one die in the walls in our front room. Oh my God the stink! I couldn't even go in for 2 weeks. It took a good 3 weeks for the smell to be completely gone. DH is a plumber and recognised the smell, otherwise I'd never have known.

Do you happen to have Homecare cover with British Gas?

We had a very different situation last year which I won't bore you with, but there was also that horrible musty smell. We phoned BG and they sent Dynorod out to check the drains first. They were clear, so we got a company in to "fog" under the floorboards which killed the smell.

We paid for the fogging, but Dynorod was paid for under our BG cover.

A couple of months ago I noticed a new musty smell in the downstairs hallway. I thought it was from the bathroom but could never work out what it was as it wasn’t a drain like smell. It seemed to move about as if it was in the air. Eventually tracked it down when I moved a cupboard and found it was mould growing up the wall behind the cupboard out of sight. Since being treated the smell has gone.

Do you put wet damp coats in there or wet shoes?

There might be a water leak on the supply pipe below the foundations.

It's been a lot less musty today, even without windows being open for most of it. The cupboard under the stairs has been modified so now only contains the hoover and tools. Any wet coats are hung on the backs of dining chairs so they can drip dry onto the vinyl flooring.

I'm not sure if we have cover through British Gas but the fogging sounds intriguing @CarrieMoonbeams!

@MrsMoastyToasty I'm hoping it's not! We had something done to the supply pipe, or at least part of it, many years ago when there was a leak near the pavement. Annoyingly, I can't remember quite what was done to the supply pipe and nor can DH.

It's funny @SE13Mummy but DH couldn't smell the mustiness at all, and yet it went on for about a fortnight and was making me feel quite sick. Obviously my sense of smell is yet another area where I'm superior to him!

Glad yours seems to be better now.