Installing terminal vent (cooker hood) onto flat felt roof

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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
 
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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.
 
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oft.aspx


I should have added this before, but the vent is a single piece with an integrated flange - would i still need the lead slate?
 
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Yes, flange will need to sit 150mm above roof, which is how high sleeve of lead slate will be.
 
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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.
 
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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.
 
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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.
 
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Yes definitely down to the felter and not really a diy job.. unless you want to burn your house down of course..
 
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