plating, anodizing, & finishing Q&As since 1989
Using galvanized tin for a small bathroom ceiling
May 25, 2010
Q. We are having issues with our bathroom and our ceiling has mold spots on it. We currently have drywall. We are in the process of replacing and rerouting our ceiling exhaust fan and will be replacing the entire ceiling. I like rustic decor and am considering getting galvanized tin for the ceiling. Will this be OK? We already have ceramic tile surrounding our shower stall, so the tin won't be directly over the shower.Jill Sinn
working mom - Sparta, Illinois, United States
May 28, 2010
A. Semantics, but you can not galvanize tin as it melts at a higher temp than tin. "tin cans" used to be steel with a thin tin coating and are not tin. That coating has virtually been replaced by organic coatings.
With the amount of moisture from baths or showers, that area is guaranteed to rust-someday- if you put up galvanized steel. This could be days, weeks or years, depending on the quality and the environment.
- Navarre, Florida
June 1, 2010
A. Yes, it is semantics. People use the slang word "tin" to refer to steel sheet metal, and it can be a bit confusing. Galvanized roofing will last many years or several decades outdoors, however:
1). It is not considered failure or rusting if the coating turns brown, due to its zinc-iron nature, whereas you might consider it unacceptable.
2.) Plenty of air (carbon dioxide) is required for galvanizing to work well. Voluminous white rust (wet storage stain) results if it can't breathe and I'm not sure if the ceiling will breathe well enough. But I have read stories in handyman magazines of it being used successfully.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey