Use your putty knife or scraper to scrape off any peeling paint or accumulated rust on your metal roof.
Painting galvanised steel roof.
Acrylics are also more flexible than oil and thus handle movement in the metal better.
Many metal roofs are made out of galvanized metal which is a type of metal that has been covered with hot zinc in order to protect it from the weather.
Painting a galvanized steel panel roof is not all that different from painting other metal objects but you must ensure that the surface is perfectly clean before beginning the application process.
To ensure that you know what kind of metal your roof is made out of and what kind of paint you should use ask a professional roofer to inspect your home.
Using your exterior metal acrylic based paint using the same paint tray that has been emptied of any remaining primer begin to apply the paint with a roller directly onto the galvanized steel roof panels in the same order you applied the primer.
If you re attempting to paint siding panels roof flashing or other materials that have seen exposure to the elements a thorough cleaning is necessary to eliminate any organic contaminants from the outer surface.
Get off as much paint or rust as you can.
If you have a kitchen then you probably already have this handy solution.
Find either oil based or acrylic based paint at your local home improvement store.
However paint on metal roofs often peels or rusts in which case it is time to repaint it.
Painted metal roofs come with a baked on factory finish and you can re coat these as well as paint bare metal roofing with acrylic latex paint.
Galvanized metal roofs are usually painted with acrylic based paint.
Certain roofing materials such as terne tin and galvanized steel accept waterborne coatings more readily than oil based coatings.
The secret to painting galvanized steel is white vinegar.
White vinegar is both effective and non toxic so it is much safer to use than your average industrial solvent.
They are also faster to dry allowing a painter to turn a job around quicker.
Common household products like comet mineral spirits and chlorine bleach can all be used to prepare galvanized steel for painting.
You can also use oil based alkyd paint but.
Rather this is just a phenomenon that often occurs in galvanized materials due to intermetallic alloying of iron and zinc i understand and is not indicative of the end of the useful life of the galvanizing.