Installing terminal vent (cooker hood) onto flat felt roof

[Atom_Smasher]

Hi all,

I would like to install a terminal vent (Ubbink OFT-1F) for my cooker hood onto the roof of my extension, which is built up felt. The vent has a integral plastic flange.

I'm fine with cutting a hole through the roof as required but i was wondering if someone could tell me what i should be doing with the felt...

Thanks

 

[Elastomeric]

Weathering slate, preferably lead, primed and felted in.

 

[noseall]

A flat roofer would typically cut a square of roofing material around the exit hole enough to seat a vertical lead slate plus some wriggle room. It would then be re-felted (sealed) around the lead slate.

You would fit your vent pipe through and then fit a plastic skirt or a mushroom cowl (or both) on top the pipe. However, the vent kit is likely to be 125mm so plan accordingly as this is non-standard size.

 

[Atom_Smasher]

I should have added this before, but the vent is a single piece with an integrated flange - would i still need the lead slate?

 

[Elastomeric]

Yes, flange will need to sit 150mm above roof, which is how high sleeve of lead slate will be.

 

[noseall]

It appears like the item in the image is a 1 piece weathering kit. Looks to me as though this just gets felted in. Yeah crack on you seem to have everything there.

 

[Elastomeric]

It appears like the item in the image is a 1 piece weathering kit. Looks to me as though this just gets felted in. Yeah crack on you seem to have everything there.

Looks plastic to me...Felt will have metal flange.

http://www.ubbink.co.uk/products/Ro...Flat-roof-(1)/OFT-Vent-and-Terminals-(1).aspx

 

[noseall]

Looks plastic to me...Felt will have metal flange.

It looks like similar material to a balcony outlet. Many of these are a plastic compound and are designed with hot felt application in mind.

 

[datarebal]

Lead slate as already suggested. but I have seen these fail at the lead felt join.. even primed.. Obviously down to the felter.
Or you can form a timber box felted in with an upstand , then a lead slate dressed over the top on four sides. No dissimilar Mats to consider.

 

[Elastomeric]

Lead slate as already suggested. but I have seen these fail at the lead felt join.. even primed.. Obviously down to the felter.
Or you can form a timber box felted in with an upstand , then a lead slate dressed over the top on four sides. No dissimilar Mats to consider.

Down to the felter, that's the magic bit.

 

[datarebal]

Yes definitely down to the felter and not really a diy job.. unless you want to burn your house down of course..