Home constructions and renovations

Odd odour in just one room—what could be causing it?

Anonymous user 22/07/2026 - 9:53 AM

Hi there, Hoping someone can help us out. We've been dealing with a strange smell in one of our upstairs bedrooms for quite a while now. It doesn’t seem to affect any other part of the house—just this one room. The smell comes and goes, and it's especially strong during warm and humid weather. It’s a fishy/ammonia scent, and we've already ruled out any electrical issues or problems with plastic light fittings. At first, we couldn’t pinpoint the source, but it seems like it might be coming from one corner at the front of the room, which is adjacent to our neighbour's upstairs bedroom. Over the weekend, we moved the furniture, pulled back the carpet, and took out a few floorboards. We think the smell is originating from beneath the floorboards, but we're stumped on what to do next since nothing is glaringly obvious. There’s a slight whiteness on the wooden beams, but that might just be plaster residue from the ceiling below. Can anyone offer some advice or suggest who we should contact to help us figure out where this smell is coming from and what’s causing it? It's driving us crazy! Our house is a 1930s semi-detached.