Roof steel rust issues: We recently installed a concrete tile roof. The builder used untreated steel for the structural supports (SCG brand), and did a mediocre job painting with gray primer (TOA Shark). The steel supports are up, tile is on the roof, and the steel is already showing some red surface rust in places.
(I know, it is my fault for not checking the correct way to do it. Just trying to find a solution, if needed.)
The solution to the rust issue that the builder offered is to use a paint sprayer and spray more gray primer everywhere, including over the surface rust. (It's also messy and the paint spray gets on adjacent areas of the building.)
In my view, spraying primer everywhere will not solve the problem of the rust coming in, will never cover all the steel because there are areas it can't reach, AND it just makes the problem worse, because now we can't even see where the rust is starting to form.
Anyways, I am trying to get an idea of how serious an issue this is.
First, is it a common problem to have rusting of the steel supports in a roof? Should I not be shocked?
If the rust is just fed by air moisture, will the progress be slow enough that I don't have to worry for many years?
Should I be most concerned about where joints and welds are?
What's the worst that can happen?
Has anybody else seen this problem in your roof supports? What did you do?
I know, it is my fault for not checking before the installation, if I knew then what I knew now! I have learned a lot about roof installations, unfortunately too late.
This is a bit of a crisis, sorry for the long post, I really appreciate any help.
Thanks for any help.