This is a follow-up to my other question. My house has a wood frame and vinyl siding.
Installer came out to do a range hood install and for the outdoor vent cap he just sealed it with silicone to the siding. Allegedly he sealed the duct opening to the sheathing as well, but I have no way of knowing unless I take it down.
I'm worried about the weatherproofing of the job, so I've frantically been doing research on how to fix it. I think I have figured out how best to do it:
- Cut a square hole in the siding
- Remove a few pieces of siding in the work area
- Cut diagonally to create a flap in the house wrap on the top side of the vent hole
- Silicone the top and sides (not bottom) of the vent cap and screw it into the wall
- Seal the sides, then the top of the vent to the wall with flashing tape - top strip goes directly on the wood under the flap of house wrap
- Reattach the house wrap over the top of the vent and reseal with house wrap tape
- Surround the vent with J channel, tape the flange of the top J channel piece with house wrap tape
- Reattach siding
- From the other side of the wall, fill the gap between the duct and the exterior wall with firestop foam
Here is a crude graphical depiction of what I'm thinking of.
TLDR: Flash it like a window, use J channel trim, foam to seal the air gap
Does this sound reasonable? Is there any gotchas I've overlooked?
Additionally, I'm a little confused about how to approach the "not sealing the bottom" guideline regarding the gap in the exterior wall. Should I not be sealing it all around somehow?
My references:
