Bathroom Extractor Fan - Ceiling mounted

29 Mar 2008
Reaction score
United Kingdom
Hi Chaps,

I am fitting a new bathroom. The ceiling of the bathroom will slope as it is in the loft and will follow the line of the rafters. The shower will be away from the external wall on the other side of the bathroom as I need the height afforded by the slope of the roof in order to stand under the shower.

My initial intent was to fit a ceiling mounted extractor fan above the shower that will vent through the roof tiles directly above it. The problem is that all the extractors ceiling mounted extractors I can find run a pipe through the loft and vent through the eves - I won't have a loft and so can't use them.

Does anyone know of a good solution, or am I better off with a wall mounted fan? This would be about 3 foot from the shower and I would worry that steam and condensation would gather above the shower as this will be the highest part of the ceiling and a foot or 2 above the maximum height at which I could install a wall mounted extractor fan.

Sponsored Links
Wall mounted fans are fine.

Calculate the volume of the room: height x length x width. Average bathroom will be approximately 9m3. An average 100mm extract fan will move 0.04m3/second of air. Therefore this will change the air 16 times an hour or once every 3.75 minutes, plenty!!

Vent Axia make higher performance 100mm fans if this is not enough!

So you don't think I'd get a problem with damp or mould along the high side of the bathroom celling, given that the wall mounted extractor will be about a foot and a half lower than than the highest point in the room?

Building Regs recommend a minimum extract rate of 6-10 air changes per hour for a shower room.

it's not all about where the extractor is, but how quickly it extracts. Mould and mildrew will only grow in constantly damp conditions.

Just make sure the extracted air can be made up, usually by leaving a 20mm or so gap underneath the door!

Basically the higher performance fan, the better.
Sponsored Links
We have a sloped ceiling in an extension, with a roof vented ceiling fan.

We wish we had chosen a wall fan because the roof vent (brown square cap) catches the wind and forces cold air in - even with a draught excluder... Why anyone would want a fan vented like this I don't know. Wall every time for me!

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local