Fascia venting (again)

[Tim Watts]

Hi,

Anyone familiar with these:

?Recap - need to vent the dormer facias, there is no soffit, so has to go in the fascias.

I presume these are designed to screw to the top of uPVC fascias?

I guess these things might be retro-fittable if I can get the uPVC fascia off (ie is the roof felt stuck to it or not - only trying will tell[1]), sticking one of these on top and refitting the fascia dropped by about an inch. OK it will no longer line up with the edge fascias, but I don't think anyone will notice at that height.

[1] If the felt (which was hot-tarred on) is, is it viable to release the felt by application of a suitable gas torch?

The other option is hole-sawing or jisawing big holes in the front and gluing a louvred gas vent+insect screen on - but I'm less confident about the air flow and rain proofness of that idea...

And there was another option John R came up with last time round of using flat ventilation 90 degree turns as rain proofing, but that, while very convincing will be a bit fiddly too.

[John Rumm]

Or use a vent tile, or strip some tiles, and replace the under felt with breathable one.

You could always chop a bit off the top of the facia

Ah, is this a flat roof?

Sticking the stuff with a gas torch is easy enough - not sure I would want to try and free one though!

Seeing if it can be prised off cold would probably be easier.

or multimastering - you know you want to ;-)

Louvred vents with the fins pointing down is probably the best you will achieve in that respect... I ought to be no worse than an air brick.

If you are taking the facia off, then it would be fairly easy to cut a slot and poke one end of a L shaped vent through from the back. Allowing air in, but requiring water to make a vertical ascent after entry.

[Tim Watts]

Yes...

Good news... I've just managed to lean far enough out of an upstairs window to get a bit of a look underneath. The felt hangs into or over the gutter (I think, couldn't see that bit). The fascia b

[Tim Watts]

The fascia board is in the clear. Interestingly, something I hadn't noticed before. There is 20-30mm wide infill between the fascia and the top of the wall tiles (like a micro soffit). The fascia overhangs it by about an inch. Another option might be to have that strip out and replace with a strip of metal insect mesh which would allow a lovely airflow up there and the fascia overhangs well enough to stop rain getting up there.

I'll see if I can get some photos. Probably still be easier to de-nail the fascia and remove the plastic gutter first, to get it out cleanly and to get a good fit with the mesh. But that's looking like an attractive idea.

Yes I had considered the option of removing the fascia, modding it at ground level and refitting it. I did wonder how wibbly it would get with all those holes chopped in it!

On an aside, re fitting celotex in the deep dark recesses here:

between the rafters in that 1m deep void to the right (I have 7m length of such voids!)...

I have just located a supplier of a foam gun with a 31" barrel, rated for PU foam, standard can fitment.

It's going to cost, mostly the shipping from the USA is more than the gun's worth, but I rate it as essential here. You couldn't even get the celotex in in one cut piece into some of those areas - I reckoned on one of those voids needing maybe 3-4 cut pieces foamed in just to do 400mm x about 1000mm.

It's a yuk job alright. Someways, I wish the roof was knackered and thus I'd have budgeted for re-tiling/refelting - 'cos then I'd just have a warm deck job done (ie celotex on the top of the rafters) instead which would be the best way by far...

Tube on a gun isn't going to cut it - too many bits of conduit coming up by the wall plate that I don;t want to get covered in foam!

[Kipper at sea]

The units you see in the link are over fascia vent strips. They are designed to fit on top of a fascia board under the vapour of underlay felt on a tiled roof. They can either be nailed or screwed on; they also interlock at the ends. When fitting, the back edge fits flush with the back edge of the fascia board and the front of the unit hangs over the front of the fascia board to form the vent cross flow. Theses unit are NOT designed for flat roofs. Don=92t put a blowtorch anywhere near the units on an eave.

[Tim Watts]

Theses

:(

OK - thanks for clearing that up.

Figures ;-O