Wet cement smell in bathroom after shower/bath (one for PigletJohn)

[MammaDramaLlama]

Just moved into our new house and the top floor bathroom has a sort of musty wet cement type smell after anyone takes a bath. Any ideas what might be the cause and what I can do to investigate? @pigletjohn

What sort of extractor fan have you got, and how long do you run it?

Do you have access to the room below, to spot marks from leaks?

We have an overhead one that is motion activated. Yes, we have access to the room below and there are no leaks seeping through.

So your motion-activated fan will go off after you leave the room, and possibly while you are in the bath if not active.

Does it have a run-on time delay?

Can you show me a photo of it?

Can you see the external grille where the steam is supposed to come out? Do the flaps open when the fan starts?

You mention smell of wet cement. Wet brickwork smells different to wet plaster, can you tell the difference?

Wet brickwork is more likely a leak.

Wet plaster might be condensation on the ceiling, often because it is not well-insulated above. Can you look in the loft? Sloping ceilings are often badly insulated.

If you are using a shower, water might be leaking round unsealed gaps, often where the tray, bath or enclosure meets the wall.

How old is the house?

I've attached a photo of the exhaust. I can't see a grille externally to know if it's opening properly. It is a bathroom in the loft so might be an insulation issue. I can't tell the difference between wet plaster or wet brickwork 😅

I did open the bath cover and look under into the pipework and there isn't any leak there but that's not to say it may not be further down.

Forgot to say, house is Victorian circa 1890

Was the smell there during the long warm summer we just had?

That looks to me like a picture of the fan inside the bathroom ( the inlet). Not sure which way is up.

The exhaust is where the steam comes out, and is (should be) outside the house. I am alarmed if such an exhaust is not visible.

Can you see into the loft?
And look at the duct?

I have no idea. We just moved in :-). It only comes on after someone's had a bath/shower and then dissipates after that (so not a continuous thing)

Happy sigh that PigletJohn is still handing out sound advice.

If it’s in the loft, can you see a pipe coming out of the roof roughly where the e tractor fan is?
have you been into the loft to check the extractor fan is connected to anything at all?
is the extractor fan motion activated or does it come on with the bathroom light?

What happens is you just run the cold bath tap or the shower on cold?

That might give an indication if it’s a water in or water out pipes leaving the bath/shower that aren’t connected properly and leaking type issue or if it’s a condensation issue only brought on by steam?

That's a really good suggestion. I'll run a few experiments and get back