Matt N
8/19/2008
Hello Experts! I have a question about an old tin roof. I'll give some background, and then a list of questions below: ===BACKGROUND=== My family owns a house in upstate New York with an old, flat tin-plated (or perhaps terne) metal roof (exact age unknown, roughly 100 years). It was my grandmother's house, and she apparently employed a somewhat incompetent roofer, who painted it with an aluminum/tar based paint that caused an electrolytic reaction with the tin/steel in the original roof. Eventually, leaks formed, and sealing them with mebrane and tar seemed only to lock water in and make the rusting worse. After several years of work, we have removed much of the aluminum paint and covered the roof in an oil-based paint, restoring it to its original red appearance. However, one small part of the roof near the drain deteriorated fairly significantly, and in some sections, the aluminum and tar are still firmly stuck on (though the aluminum continues to peel, and we continue to work at removing it). Last year, I finally stripped off all of the old tar patches from the worst sections, found the leaks, and soldered on new metal sheets to patch them. However, I also noticed that the mouth of the drain is apparently made of copper (not iron), even though it comes out overtop of the terne sheeting and attaches to the steel drainpipe of the main house. It was attached simply by nailing it down, and spreading tar over it. Not wanting to solder it (because it is a different type of metal from the roof), I just resealed around it with tar, but it's started to leak some again. So, at this point I have a few questions: ===QUESTIONS=== 1) I used galvanized steel to patch the roof (I tried to sand off the surface coating where the patches are soldered to the roof). Strictly speaking, it seems like it would be better to use terne. I can remove the patches and solder on new ones, but I am not sure where to get terne sheets. Any suggestions? 2) I am interested in the possibility of using an elastomeric coating like Acrymax to protect the roof in the future and to seal any remaining damage. Is it appropriate to apply Acrymax overtop of the remaining peeling aluminum paint, or is it necessary to completely remove it before applying an elastomeric coating? I'm guessing the latter), and I'd be very interested to know if you are aware of an effective system for removing aluminum/tar based paint from a tin roof. We've tried scraping with wire brushes, paint stripper, turpentine, etc, and I worry it may actually put stress on the old solder seams more than anything else. 3) Although the roof is about 1700 square feet total, only that smaller area around the drain(about 400 square feet) has much damage or leaking. Would be appropriate to apply Acrymax only to this smaller part? Do you have any idea what the price difference might be? 4) What do you suggest I do about the mouth of the drain. Currently, it's the only part that's leaking, and I have a feeling it was not installed correctly in the first place. But I don't want to solder it down or just slop tar over it again. Thanks in advance for ANY advice anyone is able to offer. Matt
Todd Miller
Classic Products, Inc.
8/26/2008
1) Follansbee Steel provides terne metal. 2) I do not know about the compatibility of elastomerics over your existing. I know that generally they need a clean dry well adhered surface to go over. I would suggest checking with the manufacturer of the coating that you wish to use. 3)I believe that you could use elastomeric just on that area. Also, some elastomerics come with a scrim that gets embedded in them and that could be good. You may wish to google "metal roof restoration" 4) You might try a high quality butyl or urethane sealant.
Guest User
8/26/2008
Thanks a lot for the response -- I appreciate it!
Find a Contractor

Get Started Today

Take the first step to increasing the value of your home with a great looking, durable, fire resistant and energy efficient metal roof. Browse our list of qualified MRA Member Roofing Contractors in your area for a free consultation and estimate.