1st floor Bathroom ventilation with loft room above

[xyz123]

Hi, I asked this earlier as part of few questions on loft conversion but just wanted to ask a specific question

We are in semi detached house with bathroom on 1st floor. Bathroom had a wall mounted vent fan that was quote useless so I replaced it with an online fan. Mounted in loft and venting through duct outside. It works very well.

Now we are looking at converting loft into a proper room and 2nd bathroom directly above existing 1st floor Bathroom. Other than re-instating wall mounted fan, is there any other solution that I am Missing (other than PIV) ? There is about 8 inch of space in joist in new loft floor but I can't see how I can mount a fan in there with a duct and still retain some form of access to fan in case of any issues? Am I missing something here?

Thanks

[Metric Max]

Would flat trunking like this help?

https://www.toolstation.com/100-flat-channel/p3963...

[DorsetSparky]

More powerful (centrifugal?) wall-mounted fan.

[Simon_GH]

Fan with roof exit? Our bathrooms extract to roof vents.

[Mr.Grooler]

We have a first floor bathroom above a small toilet room downstairs, and fitted a ceiling extractor in the toilet room that vents up a pipe from ground floor into the roof space adjacent to the soil stack; if you have a boxed-in soil stack rather than a pipe outside, perhaps that's an option too?

Could you hide a decent sized in-line fan inside a cupboard in the loft bathroom, that extracts from the bathroom below? (The small fans not being great, usually)

Edited by Mr.Grooler on Tuesday 25th March 22:56

[OutInTheShed]

Fan in cupboard in upstairs bathroom?
Behind bath panel if it's and actual bathroom?

You could put the fan under the eaves, wouldn't be my choice to need a ladder to change the fan, but it's an option.

Personally, I might look at some kind of MVHR system at the same time, it should be fairly easy to design in any ducting required.
These things are more mainstream now and prices have come down a fair bit.