In message .com,
sm_jamieson writes
I need to fit a bathroom extractor fan, and don't want a direct air
path through-the-wall unit, due to the problems with them letting in
the gales (even the ones with flaps which clatter).
So I want to fit a ceiling / soffit vent type. The problem is, the
soffit is very shallow, only about 4 inches, and the space inside the
wooden box of the soffit would only allow a vent about 2 inches deep.
Could I use a long thin vent under the soffit without problems ?
Or any other ideas for a non-direct air path through the wall (solid 9"
masonry).

Could you go through the roof?

I vented my bathroom extractor in my last house up through the ceiling
and through the roof.

used an inline unit mounted in the loft. connected the end of the
flexible pipe to one side of a soil pipe elbow. Ran a length of soilpipe
up through the roof, use a 'weathering slate' - a malleable aluminium
plate with a rubber seal to pass the pipe through. terminated in
mushroom cap type vent on the end of the pipe. Secured the soil pipe at
the base to where it passed between the joists.
--
Chris French