Odd smell in house! Unsure who to hire to investigate

[SerenaOverjoyed]

About a year ago we ripped up the carpet on our stairs and noticed an odd gassy smell (like onions/savoury), largely from our cupboard under the stairs with is right over the subfloor. There's a pattern of it starting at about 6.45pm and dispersing by 7.30, and not every day Sometimes I notice it on the odd morning but rarely. Might be a pattern with wetter weather but it's not every day so it's hard to tell.

We had a damp specialist in last year who said no damp/rot in the subfloor (he stuck his head under the boards with a torch!). We had the drains cleared. We have 3 airbricks which are clear.. but it still happens.

I'm at a loss and it's making me hate living here. Not sure who to contact to investigate? I wonder if it's a cracked pipe, or electrics? Or sewage related? Or just next door cooking?!

Oh, it's not gas. We did have a gas leak there 10mo ago but this is fixed. I've called gas emergency 3x since on smelling it but there's no leak

I would get the gasboard to check. Speaking as someone who ignored an odd intermittent smell until the day it was overwhelming when we discovered the mains gas supply running under our floorboards (old house) had ruptured!! Had to evacuate my neighbours!!

Have you got any capped off old sections of pipe under there? If they had a leak there could just be small amounts coming out that wouldn’t show when mains was tested??

Are you in a terrace? We get that and it is the neighbours cooking, I guess cus of had puppies etc the smell just comes straight through from next door

We are in a victorian terrace, as the cupboard is the closest bit in the house to their kitchen we thought it might be this?

There is an old capped off bit for gas where there was a gas fire. How do I call the gas board snd how would they investigate?

I think the gas board would only check mains-you’d probably need to pay someone to check it. I think given the timings a smell coming from next door is more likely.

Oh my typos It's not gas, but where the gas pipes enter our house are good so I guess the smell comes in through these gaps. So, it's not an issue for the gas board, more for you to see if you need to fill in the gaps

I remember when we ripped up the carpet I removed an old moth ridden carpet and bits of newspaper from gaps, thinking this was for mouse proofing. It was probably for the smell!

Dead rodents can smell gassy.