Strange smell returns!

[mypinkmonkey]

Have posted about this before- get strange smell in house for couple of hours every morning - mainly in downstairs hallway. Smell dissipates gradually over the morning. Have checked boiler - that's ok and it is in outside cupboard at other end of house. Also checked light fittings.
Have worked out this week that it occurs about half hour after I have a shower so I am guessing it is something to do with water pipes to my bedroom. But there's no leaks showing anywhere(yet!)
I know where pipes run - we did a major house renovation two years ago but don't want to pull flooring up randomly.
I suppose best option is to wait for the leak to show!
Advice much appreciated. TIA.

how effective is the extractor fan for the shower?

quite probable that you have water leaking from the sealant against the wall or tray, or from the waste under the tray. The sooner you fix it the less rot you will have. I take it there are no marks showing on the ceiling below yet. If you turn on the shower (cold) and leave it running for a while, there might be enough water to show. If you can look under the nearby carpet or other floor covering you might see something.

p.s.

if it is an electric shower, see if the smell only happens when you are running it hot (using the heating element) or if it happens cold as well.

Have you considered the possibility that an exterior sewage pipe is part blocked or cracked?

We had a problem similar to this a few years back & it was a near neighbors pipe that was cracked and when heavy usage a smell used to linger outside and sometimes inside.

They had a camera put down and it showed a joint had gone and stuff was backing up, as soon as nobody was using water or toilets it subsides.

I am assuming you get the smell in other rooms than the bathroom.

A broken pipe can cause subsidence

I would also have a look at the pull cord switch that will wired in the loft space. A fishy smell emanates from plastic that is getting hot

Just noticed you mention you can smell in the hallway, so my first guess could well be right a part blocked pipe or cracked somewhere on route

A clue might be that next time you get the smell run both the kitchen taps and bath and see what the speed of water leaving is . If there is a bad blockage the it will probably show signs or slower flow away down the sink and bath

roneik and PigletJohn - Many thanks for your advice. Will give your suggestions a try and report back.