My house has a modified bitumen membrane roof, at a very low pitch/nearly flat, which was repainted with aluminum asphalt paint a couple years ago. My friend is considering painting a mural on the roof itself (if you must know, one draft is: a giant medusa head over an ocean, with the roof ventilator as a third eye, the snake hair forming a walking meditation labyrinth, etc.) Ideally we'd like the resulting painted mural to:
- be hard-wearing enough to support occasional foot traffic (we hang out on the roof sometimes)
- be long lasting (This is in New York City, so we're dealing with a wide range of temperatures/weather conditions, from below freezing and mounds of snow to swelteringly hot 100% humidity torrential rain)
- provide reasonably decent reflective insulation and protect the roof against UV damage as compared to the current aluminium coating (if possible - I know it won't be as good though)
I'm not sure where to begin in selecting paint for this. Acrylic paints are generally used for wall murals. I expect we might have to mix our own colors which is ok.
Also not sure what preparations would make sense apart from thoroughly cleaning the roof. Glossy aluminum paint maybe means a new coat wouldn't stick well, so we could dull it by using an abrasive cleaner.
What do you guys think?