There are times when building owners become interested in repainting their current metal roofs. This may be to freshen up the building or to give it an entirely new look and color scheme. Most quality metal roofs have finishes that are warranted for 40 or more years. Repainting of course will void any warranty that may still be in effect. As long as the roof’s current coating is adhered to well and not peeling or flaking, it should provide a good base for repainting. We suggest first lightly power washing the roof with a mixture of water, trisodium phosphate, and detergent. Then a primer should be sprayed on and allowed to dry followed by the same thing with the topcoat. We generally suggest going to a quality name brand paint store and using the paint system they recommend. For folks wanting a longer-lasting finish, there are air-dry PVDF coatings available. We warn consumers though that in very few cases will the repainted finish last as long as the roof’s initial coating.
For the purposes of this question, we are going to break down the types of metal roofing based on the roofing materials.