I've got an extractor fan in the bathroom. He's been in there for ages, hope he's ok.
I've also got and extractor fan in there. At the moment the set up is a fan in the ceiling venting through flexible duct in the loft and exiting downwards through the soffit. Its a fairly bodge-looking arrangement at present and we often get water dripping back through the fan so I guess the whole setup is less than perfect
I'm just about to get the roof re-tiled and the soffits redone so wondering while this is being done if its smarter, more efficient for the extractor to be venting upwards through an outlet in the roof? Or repeat the current arrangement and vent downwards through the soffit? Or does it not matter... or are neither of those option optimal and is an extractor venting out through the wall (with less ducting) more efficient, whilst also interfering less with the weather tightness of the roof.
This may be the most boring thing I've ever posted
EDIT - what if I liven it up with a gif for our new gif button
Boom!
Wet air pumped into the loft space can cause issues long term depending on how often your bathroom gets really steamed up. That water dripping back down would just stay in the loft by the sounds of it if you simply improved extraction/ducting.
And the water dripping back doen through the fan is also a clear issue.
So I agree something needs to be done, and the best time to do it is whilst you already have works going on for the roof.
But I'm not sure what the best 'something is'... it probably needs someone who knows what they are looking at to appraise the extraction set up.
The most direct, short way is the best. Every bit of ducting reduces the efficiency. So, through the wall is best. If going up and out through the soffit, an insulated duct, and / or a duct drip/drain fitting to catch any condensed water running back into the fan. You may get away with a 4” fan through the wall, going up and out will need at least 5” / 125mm.
Wet air pumped into the loft space can cause issues long term depending on how often your bathroom gets really steamed up. That water dripping back down would just stay in the loft by the sounds of it if you simply improved extraction/ducting.
At the moment anything going up is leaving the loft via the soffit, so that drip back is only the first foot or so before it makes the turn, but I don't doubt moisture will be sitting in the horizontal run - especially as it is just flexable duct so undulating on the horizontal.
The loft itself is well ventilated at present - clay tiles directly onto sarking - but with the re-roof it'll get vapour barrier, so will be less breezy than it is at present, so the extraction would want to be better specced.
With the rest of the roof we're getting rid of any fiddly bit that might later cause a leak - chimney is going so theres no flashing fail, getting rid of the skylight because its a loft and we keep all our hostages in the cellar, diverting the top of the soil pipe - which currently punches through the soffit and roof rather than just have a little bend in it and so on (the tiles around this bit, on mine and all my neighbours roofs blew off in storm whassname)
So sticking a pipe through the roof for the extractor seems to run contrary to those efforts. The only reason to do it really is if going up is better than going out through the wall - but I suspect 'out through the wall' is actually the smarter way to do it and keep the roof as simply and tidy as possible
Have another gif from the STW gif library
By the sounds of it you’ve got the extractor fan mounted on the ceiling? If that’s the case change it to an inline fan mounted in the loft with the exhaust part of the ducting pulled tight and with some fall towards the soffit. You can also set it to overrun for longer as it will be quieter which will stop the drips falling back in
Through the wall.
Once a year you can easily reach the fan, pull the grill off and clean all the crax out of it.
Becomes less efficient with a build up of damp congealed dust.
I agree with marks park, if you are re roofing then get an in line fan put it along with some rigid ducting if you can. More powerful extractor and overrun setting should sort the drip and give better extraction than you currently have
A nice powerful inline fan will sort that. Insulating the ducting should help during colder months, as well.
