Deciding on a new roof is not a simple as black and white.

I need a new roof and like most houses in the desert Southwest mine has a foam roof. I’ve got no complaints about foam but one of the bids I’ve received wants to use bitumen instead of foam. (Bitumen (or asphalt) is a sticky, black, and viscous liquid or semi-solid form of petroleum.)

I’ve done some internet research on bitumen but mostly the info talks about its durability in the parts of the country that don’t get as hot as the desert Southwest. Since the seams for the bitumen underlayment are heat-sealed I wonder if the seams will stand up to the intense heat of the AZ summers, or will they liquefy and loosen allowing rain to enter through the seams? In the summer we can get rain when it’s 100 degrees or higher. Bitumen is black, meaning it absorbs heat more than the white of a foam roof. Our electric bill with the solar system we installed is nearly negligible so while energy use is a consideration, it’s not a real concern. Bitumen being a petroleum product is more of a turn-off for me than energy use with a black roof.

Also, the summer heat creates micro cracks in the stucco on the top of the roof parapets. These micro cracks enable rain to fall between the exterior and interior walls which then seep out onto the floors. I have had the parapets re-stuccoed many times but that treatment has never lasted more than one or two summer seasons so I am thinking of including treatment of the parapets with whatever roof treatment I choose. Does anyone have another product suggestion?

Don’t see many houses with bitumen roofs in AZ. Does any DUer have a bitumen roof or know someone who has a bitumen roof on their house?

Cost is less of an issue in my decision-making process than the product’s reliability and longevity. All suggestions and comments are welcome. A new roof is a hefty financial investment so I’d like to get as many thoughts as I can before making a decision.

Thanks.