Help with failing exterior finishes

摘要

QMy house has a metal roof. The metal is good, but there's a lot of surface rust. I've had it painted twice in the past 30 years, most recently about six years ago. I think the painters sprayed on an oil-based paint. It looked good for a while, but now there's a lot of rust coming through. Do you have any suggestions? A Contributing writer Scott Gibson replies: The paint could be failing for one of several reasons: sloppy prep work, the wrong product, or improper application. Unless there are other problems, however, it will be more economical to have the roof painted a third time than to replace it. That's what I gathered from talking with several experts, including Todd Miller, president of Classic Metal Roofing Systems and a founder of the Metal Roofing Alliance, a trade group for the residential metal-roofing industry. According to Miller, a repainted roof should last as long as 20 years.