What kind of corrosion is this and what caused it?

Good link Marcel, where do you *find *these things!?

I’ve watched him, over the last couple o’ years, master Google. He always has good pertinent info. Nice Marcel…:smiley:

Very interesting: Thanks for posting

Grat post!! much information. I did cheat, went to the end of the post first to get the answer!!!

Thanks, we can all learn from others!!!

Thanks guys,

When it becomes available… take the Roof Defect Recognition course. All the steep-slope residential roof-covering materials will be covered in this kind of detail. No insurance agent or roofing contractor will be able to win an argument with you when it comes to these common residential roofing materials. You will know what you’re talking about.

Hi. Kenton; Cann’t wait, you always put together good material.
Glad you like the link.
I am just getting back from my out of State job.
Bel glad when working local again.
Awwell, it is a job. :mrgreen::):smiley: