new bathroom fan in loft - no room at the eaves

Anything here (or from similar suppliers) worth considering:

Many of the new builds round here seem to have two or three ventilated tiles in their roofs.

It's up to you. It could be best starting a new thread for your convenience if you want to keep it all under one obvious subject that you might want to refer to later. Anyway, the way threads drift off subject here and elsewhere means it probably won't matter in the long run!

Xan you transition to rectangular ducting for the exit, either rigid or flexible type?

Andy Burns snipped-for-privacy@andyburns.uk wrote in news: snipped-for-privacy@mid.individual.net:

Or indeed super slim versions eg. 234x29:

Plenty of useful adaptors/corners in the range.

For the o/p, short runs best to avoid condensation in the duct and dripping back or smelling.

fred snipped-for-privacy@for.mail wrote in news:spz9O.51303$y snipped-for-privacy@fx02.ams:

Worth shopping around for "225mm flat ducting", the Manrose version appears significantly cheaper from some sources:

As it happens I came across a similar problem yesterday. What I thought was the back of the soffit was actually the inner skin of blocks, and there's then the cavity and outer brick skin. In my case there was insulation (and a bird's nest) in the gap so I could access the soffit, but need very long arms.

Looking at a diagram (of a soffit ventilated roof, but bear with me):

Have you thought about doing it from the outside? ie take the soffit off, drill whatever hole in the bricks you need to get access to the loft.

You could use rectangular ducting to get through this gap, perhaps adapting back to circular ducting:

Looks fine to me. I'd start a separate thread as a new title it may attract those who know about electrics.

Theo

Squashing the ducting is the answer. The duct diameter is not altered hence the area enclosed though a different shape is the same, as long as you do not completely squash it flat. I did that with my inline fan and no problems it clears the vapour in the bathroom in a matter of minutes in fact by the time I am out of the shower and jumped into some clothes all glass panels and mirror are completely clear.

I'll get back later to all your questions and suggestions. Just wanted to exclaim that while it's fiddly to have to use the computer to reply it's already worth the effort to get this set up. So much better than a certain forum I will not ;-) be using again.

Not the question that you asked, but have you considered putting a non- return flap in your ducting run? Our bathroom fan duct (in line fan) in the loft is waiting for one to be fitted, because there can be quite a strong draught back through the duct. OK in summer but can lower the bathroom temperature in winter by several degrees.

Cheers

Dave R

Christ in a bike, Some needs to go back to school

I think it's worth considering, yes. I've discounted it so far and it's my least favourite option as I assume the roof is original and don't really want to disturb things if I can help it. It will need doing at some point.

Thank you I'd seen rectangular solid duct but didn't know this flexible rectangular existed!

Wasn't sure if you were using the round insulated ducting as per the video, if it's important for noise reduction to keep to a similar ducting?

I've bought round insulated, swayed a little by the video - I know technically it's sound insulation but I suspect the foil ducting is louder than solid even with the insulation. I was hoping it would instead offer some element of thermal protection and then reduce the amount of condensation (hopefully better than nothing).

I didn't buy one but thanks for mentioning it, I'm keen to hear any real experiences. I'm not against it, wanted to see if it's an issue. Does yours vent through the soffit? I was thinking the wind blowing across the soffit would create more of a suction effect if anything - and cause knocking if it were blustery. Have you gone for a straight forward type with a round disk and offset pivot?

There's a certain faff factor that kicks in. The soffit panel in question is one long piece, possibly 4-5m. I don't think I could remove this from a ladder so I'd need a tower - I also suspect whoever put it up there, "did the job" with a view that when it comes down it'll be at the end of its life... so maybe it won't come cleanly.

However, I'm considering if, once I have a 4" hole in the soffit, I could get enough access through it to make the hole. Maybe?

Yes possibly a brick's worth, if the area visible were to be removed. The grey is the ceiling plasterboard. It goes almost all the way to the brick. Using an inspection mirror there is insulation beyond the edge. The white cable just visible in the centre is the 12v feed to the existing wall mounted extractor beneath. That wall has additional boxing and the fan duct goes through the lot to outside. I'll see if I can check if that cable is coming into the wall cavity or the boxing cavity.

A few mentions for rectangular ducting. I had seen it in the TLC catalogue and I'll have to look into it some more. Wasn't sure if I could make it fit either. And fiddly work as I'd have to probably go for a few in series Round-to-rectangle converter ==> 135 degree angle ==> rectangle-to-round ... connecting some of it from the loft and trying to fit the rest/ fiddle around with it all from the soffit side without it coming apart.

With any of the rectangle profiles I assume the adaptors and bends won't interface directly and need a joining piece so it adds up.

Thanks for highlighting the super slim ducting. This is interesting and looks worth further research. These thinner ones may well do it.

Sorry I'm still trying to work out how replying and quoting works, not sure how this is going to come out

In message <v47oqn$jmkb$ snipped-for-privacy@dont-email.me, Silent Ice snipped-for-privacy@example.null writes Snip

I suppose you could utilize the existing wall outlet if it is close to the ceiling. Round duct across the loft and re-enter near the wall...

Alternatively, cut a large enough hole in the soffit to work safely from your ladder. Cover with a rectangular sheet, pre-bored to suit the extractor outlet. You are only trying to keep Sparrows out:-)

I don't know if it is an option for you, but facing a similar problem, I dropped the vent pipe through the ceiling, into the airing cupboard and then through the wall lower down.

My cupboard goes up to the (suspended) ceiling, but if I'd not put that in and still just had the original ceiling above, I could have used a piece of enamelled steel tubing to bridge the gap, like you often see for a vent or boiler in a kitchen.

The vent is directly above the bath, and goes up into the loft and out to the soffit via an in line fan and bendy tubes.

The flap is a standard one (we have them on the downstairs extractors) but I can't recall where it pivots.

Cheers

Dave R