How to protect exterior galvanized flashing?

Question

With ships, they'll bolt zinc blocks on, can I "re-galvanize" metal?

I ask as I have some flashing that was likely installed in 1938. It was galvanized and is in reasonably good shape. But replacing it would be very expensive and hard, as it laps under the stucco. What can do to extend its life? Or will it rust under the stucco first anyway, making a external treatment moot?

Here's the specific flashing, with two rows of tile removed:

rusty 1938 tile roof stucco wall flashing

@mike, expensive because of need to tear out stucco, as the flashing goes under the stucco. Local bid is $100/foot for that. — Bryce, Feb 28 '15 at 05:35
If you can get it relatively clean and flat... rustoleum can push repairs off years. — DMoore, Nov 18 '15 at 18:35
Expensive? Breaknig out stucco, lapping into old paper, getting that all water tight. — Bryce, Nov 19 '15 at 05:10

score 1 · Answer 1 · answered Jan 17 '16 at 19:21

Oh finally a picture. Thank You! Yeah, you could flash over it with galvanized, aluminum, copper or stainless. But, the problem is cutting it in. You'd want to match the cut-in on the chimney all the way up the roof slope's wall. That's to do it right.

But, plenty of guys cover the old with new to just caulk & screw the new stuff to the wall. It's asking for future problems, but if maintained (re-caulked repeatedly) can last the life of the roof.

score 0 · Answer 2 · answered Nov 18 '15 at 18:10

There are zinc-based products that claim to be a cold galvanizer. I know I have seen this one

LPS Cold Galvanize

used in some industrial maintenance shops, but I can't vouch for it's effectiveness. It sounds suitable to me. You could test it on a small area and see if sticks well without making a mess.

How to protect exterior galvanized flashing?

2 Answers2