|
|
|
|
Can copper flashing be used over existing galvonized flashing?
(Jay Spenchian) wrote in message . com...
Hi-
For the past week or so, and as I speak, we have been reroofing our
25-year old Colonial. Much of the house is brick, however, some parts
do have cedar siding. In these areas there is a lot of
roof-meeting-the-siding going on, and they had been originally flashed
with galvanized steel. However, it is impossible to remove the
flashing without severely damaging the cedar siding. We had choosen
to use copper flashing on all parts of the house, and the roofer
thought he probably could just put new copper flashing, for the new
fiberglass roof, over the existing galvanized steel flashing, which
was for the existing shake roof and is incompatable with the new roof.
So my question is, is it safe to flash a different metal on top of an
existing one? We are worried about creating current or some unforseen
problem with what should be a fairly mundane thing.
I'd appreciate a really quick reply from anyone who has an experience
at all in this, as the roofing is being done as I write this.
Thank you.
Why not cover all the bases? Roofing felt is a more significant
barrier than painting. While it's true that the copper will not be
eroded by the galvanic action with the galvanize flashing; I would
recomend placing a layer of 15# roofing felt between the galvanized
flashing and the new copper. This will keep them separated and retard
any galvanic action.
Use copper nails or 304 stainless steel, galvanic action with the new
copper flashing will eat galvanized nails in a very short time.
Good Luck!
|