I have to make several roof penetrations in a flat standing seam metal roof. I'll be running 2" and smaller EMT through the holes. I need advice on the best way to seal the holes to avoid leaks. Thanks in advance.
flat, as in no pitch? eww.
if i had to do that, i'd be looking at 3M 550 urethane type sealant,
or its equivalent, as 3M, in a fit of folly, discontinued the product.
the stuff was designed to seal boat hulls under the waterline. it works.
first, i'd stub thru the roof in a GRC nipple, unistrutted under the roof
to something structural, so it doesn't wiggle. make all the penetrations,
and then open a tube, and put a thick bead around the nipple, making
sure that surfaces are clean and oil free.
that alone, will not leak.
then i'd get a roof jack with a urethane grommet on it, put another bead
around the top of the nipple, and a continuous bead around the foot of
the roof jack on the roof surface, and slide the jack down over it, so it
wipes the urethane down the nipple, and seat the roof jack into the bead
on the roof surface, squishing it out.
i would not nail down thru the jack. using that urethane, it will never lift.
wear rubber gloves with that type of product. if you get it on anything,
it wears off, slowly. as in a couple weeks of scrubbing.
unfortunately even a simple job comes w/liability , the way the insurance industry rolls dictates the dif betwixt what we are able to do, and what we should avoid doing ~RJ~