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[Closed] Extractor fan into roof space?

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The bathroom refurb starts tomorrow. The builder has suggested running the extractor into the loft.
This doesn't sound like a great idea to me, but kits on screwfix indicate that this is done.
Whaddya think?


 
Posted : 17/09/2017 7:45 pm
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stupid idea. You WILL get condensation in the roof void. It must go outside


 
Posted : 17/09/2017 7:47 pm
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I've had mine venting into the loft space for 15 years or more and its been fine. But i have a really old house with no insulation under the roof tiles

I keep meaning to get some ducting and vent to the outside but never get around to it.

If you are getting the builders in why can' they put a grill on the soffits and run ducting through the roof space to the bathroom?


 
Posted : 17/09/2017 7:48 pm
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Out through the roof, various ways of doing this, but not terminating in the loft I would have thought.


 
Posted : 17/09/2017 7:48 pm
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Err I think you'll find they then exit via the soffets. They don't just vent into the loft.


 
Posted : 17/09/2017 7:48 pm
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Cheers TJ, that's my thinking, just want to make sure I'm not missing something.

OK so into roof space then out through hole in soffit - that sounds better.


 
Posted : 17/09/2017 7:49 pm
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Not a problem as long as you duct it out through the eaves or to a vent tile. Also a good idea to insulate the duct to avoid condensation build up in the duct.

Terminating in the loft without ducting outside is just asking for trouble. You'll encourage condensation on the roof covering.


 
Posted : 17/09/2017 7:50 pm
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You need a condensation box.


 
Posted : 17/09/2017 8:03 pm
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No, get it ducted out. He just trying to save coring the hole or doing the extra work involved.

Also don't except a cheap inline fan as it'll be neither use nor ornament. I always fit Manrose MF100 fans as they really shift the air and steam.


 
Posted : 17/09/2017 9:09 pm
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Ours goes out the loft as the ducting is fixed to a vent tile.


 
Posted : 17/09/2017 9:11 pm
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My inline Shower fan is in the loft and then vents through the soffit. Only problem is it covers the area in crap and fluff.


 
Posted : 17/09/2017 9:13 pm
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If the ducting run in the loft is long make sure it is insulated or the moist air will condense in the winter and pool. In the duct or drip back out of the fan.


 
Posted : 17/09/2017 10:24 pm
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DIYnot.com is full of tales of woe from people who have had vents straight into the attic or with over-long ducting causing condensation. It really is a bad idea to vent into the attic space, you're asking for damp problems.


 
Posted : 18/09/2017 9:03 am
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Surveyed a listed farmhouse a coupe of years ago where they had done exactly the same. The roof space was filled with a lot of fungal fruiting bodies that looked like fried eggs and timber with the bearing strength of weetabix. The owners couldn't be convinced there was any connection


 
Posted : 18/09/2017 9:20 am
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