Tubing attached to shop vac toggle switch allows you to turn it on and off with shop vac hose instead of fingers.
Yes, I have seen nails in roofs as the source of leaks, however, that is irrelevant as it's still improper.
All one has to do is point to every shingle flap on the roof-- no nails. They are all held down with roofing cement/tar. Shingles are much more flexible than aluminum, so why would aluminum not stay down with roofing cement?
But since you brought up high wind areas... in such critical installations, why wouldn't one take the extra 1/2 hour to hour to do the job correctly and remove the surrounding shingles to properly install the vent flashing. When done properly, there is only an inch or so of flashing on the bottom that is exposed to the wind, instead of 75% of the edge on 3 sides, like in the installation shown in this post.
In my opinion, this is a corner-cutting technique that has no place in a magazine with the high standards that Fine Homebuilding has.
In any case, if I was left with no other option, I would definitely use nail/screws with neoprene washers (as ABBAUSA stated) even though that is still unnecessary and improper on a correctly installed vent flashing of this type.
"A couple of roofing nails can be driven at the bottom corners of the flashing pan to ensure it stays put in high wind."
You go through all that work only to put a couple more holes in the roof for water intrusion. If the flashing won't stay down in high winds with only roofing cement/tar (like every shingle flap on the roof does) then you need a different/proper flashing.
There should never be exposed nails in any metal flashing. And no, a dap of tap/caulk on the nail head doesn't make it right.
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