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Roofing/coating/covering a curved metal roof


QUESTION: I have several curved metal roofs over dormered areas in my old house (circa 1837) that do not appear to be leaking.   The problem is that they are all rusted over and leave rust stains all over the slate roof.   I am now having the house painted and would like to take care of this problem if possible, however most of the products i have researched specify they are for flat, or low sloped roofs as product may drip in extended hot weather, mine are a semi-circle.   Can't afford another arm and a leg as I said...I'm currently getting the house painted.    Any reasonably priced ideas????
Thanx, not getting far with this internet search.

ANSWER: Hello S.R.,

My first reaction is to check to see if the metal roof areas are actually rusting through or just rusting.  a protective coating can be put over the rusty metal if it appears to have some remaining service life to help keep if from staining surfaces below as well as slow down the rust.   Your painter should be able to help you with options there.

If the metal roof areas are near the end of their life, replacment is the only option.  Curved metal roofs are a custom item but depending on the shape and size you do have options.   Because they are usually a custom size, there are virtually no premade options.   You will be best served to contact a local sheet metal fabricator for help.

---------- FOLLOW-UP ----------

QUESTION: My painter can't help, that's why I'm asking you.   I am looking for a coating to cover the metal roofs....which by itself is not a problem.   The problem comes in when you try to find anything reasonably priced that will work on CURVED roofs, as I said they are semi-circle shaped, and when reading all the material on most says not to apply to anything but flat or low-sloped roofs.
Do you know of any such product ?

I really wish I had a better answer for you.  I have never been a fan of roof coatings so I am definitely not an expert in that area.    I imagine they are not intended for sloped roofs because they will sag or move depending on slope.   Again, if you think the rust is just cosmetic, you might try a rust removal product, then a zinc rich paint, then a surface paint.   all these suggestions are for extending the roof life but will certainly not eliminate the need for future replacment.


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Jerry Iselin


I am pretty comfortable with all metal roofing related questions. We can discuss performance, application, practicality, technical and detail. It is difficult to deal with pricing issues due to the regional differences.


I started in the metal roofing industry in 1976 working for a major West Coast manufacturer. I spent the next 16 years with that organization leaving as the Vice-President and regional General Manager. In 1992 I started Metal Roof Specialties to focus on the needs of residential and small commercial customers. In my manufacturing years I focused on product introduction and sales as well as design and application. for the past 12 years I have been a regular trainer and presenter at Metalcon International conventions sponsored by the Metal Roofing Alliance and I have also performed training and demonstration area moderation for the National Roofing Contractors Association conventions. I have also been employed by a major metal roofing manufacturer for training and speaking engagements. My company specializes in metal roofing and siding only. We are a supply and install contractor as well as a retail outlet for metal roofing and siding materials.

Metal Roofing Alliance. National Roofing Contractors Association. Building Industry Association of Washington.

Green River Community College - Accounting major. University of Washington - Graduate School of Business Administration - Management Program. BHP Steel - RMC III Executive training, Melbourne, Australia / Berkeley, California.

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