# Proper way to install vent cap on vinyl siding?



## PatentPending (Aug 7, 2018)

I recently had a range hood installed in my kitchen. I know this is a DIY site, but bear with me, I figure it counts because _I'm_ having to figure this out instead of my worthless contractor. (Among other things, he appears to have lied to my face about being licensed and I keep finding problems like this one and/or code violations. At least he's agreed to come back and fix things, probably because he knows I've got him over a barrel because of the whole unlicensed thing).

Anyway, my "contractor" attached the vent caps (one for the hood, one for the make-up air) by screwing it right onto the siding and filling in the gaps with polyurethane foam. I don't believe for a second that this is the right way to do this. There's no way that is watertight (or if it is it won't remain so because the foam will degrade). My problem is I can't seem to figure out the "right" way to have him fix it.
Thoughts?


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## Nealtw (Jun 22, 2017)

Attach it to the sheeting and put a J trim around it or find a J box that fits.
https://roccommunitysummit.org/j-block-vinyl-siding-qq95.hta


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## PatentPending (Aug 7, 2018)

I'm more inclined to go with one of those mounting blocks that appear to go over the siding, rather than having to cut down to the sheeting, but I can't seem to find one big enough (8" ducts). Oh well.
Part of me is inclined to just tell him to "fix it with a mounting block or J trim" and hope for the best, but who knows if all the caulking/flashing/whatever would go in the right places. I'll never make the mistake of not actually _verifying_ that a contractor is licensed before hiring him again.


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## Nealtw (Jun 22, 2017)




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## firehawkmph (Dec 12, 2009)

There are a number of larger mounting blocks available for vinyl siding. The biggest ones are able to mount electrical services to. 
Mike Hawkins

http://www.buildersedge.com/blocks-vents/standard


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