Drain smell in wet room

[EarlyInTheMorning]

Horrible sewer-like smell coming from shower. What could this be?

clean out the waste trap first.

modern shower traps are made so you can empty them from above.

When was it installed, and when did it start to smell?

Is there a damp mark on the ceiling downstairs?

Piglet thank you for your answer; is the waste trap the metal mesh plaque? That's clean. However, something might be missing inside the drain that prevents sewage smells from coming in. I don't understand why anyone would remove that. What is it called and how can I get hold of one?

I had a stagnanty water smell in my (new) shower. Even a clean didn't seem to shift it - or it did but it came back withing a few days. We use very little soap (sensitive-skinned flowers so lots of gunky creams and moisturisers rather than soaps etc etc) so I think stuff was probably building up quickly. So I found it took a couple of goes of drain cleaner gel/bicarb/vinegar/hot water. And gone. Gone for some time now. But I put a capful of some stuff I got from Waitrose everytime I clean (ie once a week.... mostly) and it seems to have shifted it/be keeping on top of it.

there should be a water seal under the grill. here is a typical one shower traps are specially made so you can clean them from above.

Hmmm..... But how do you get to all those parts when the floor is all tiled?? The grill comes off and then as far as I can tell #2 from the diagram is missing...

shower traps are specially made so you can get at them from above.

If part 2 is missing, you will not have the seal.

If you take the removable parts, and perhaps a phot of the bit in the floor, to a plumbers merchant, they may be able to identify the brand and sell you a new unit which will include any missing parts.

Thank you. I wonder why it's missing in the first place.

it traps hair and other detritus, perhaps someone took it out to clean and lost or broke it.