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

[in2herbs]

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.

[Flash953]

1. Wouldn't you rather keep you roof white. White reflects Black absorbs heat

I have had houses in both New Mexico and Arizona and have had roof work done. With a white foam roof you're going to get the insulation properties that you wont get with a bitumen roof. Just think of all the electricity you will save with a white insulated house. I used a company called Magic roofing in Farmington New Mexico. You want a company that is bonded with the better business bureau. Don't go for someone that doesn't have the liscenses to do the job. There are a lot of crooks out there.

[jmowreader]

2. Is this bitumen roof going to be mop-on or torch-down?

I think you're probably more comfortable with a foam roof, so that's what I'd recommend you get. Mop-on roofs (they apply a layer of asphalt to the roof deck with a roofing mop, roll felt into it, add another coat of asphalt followed by more felt, then add a membrane with granules adhered to it with more asphalt. They can insulate these roofs by installing foam board (called "iso board" after the name of the plastic it's made from, which has a name as long as Trump's neckties) under the first layer of felt, and they can be white. Torch-down roofing is built-up like a mop-on roof but they bond it by heating the underside of the membranes with a flamethrower until the asphalt melts before they stick it to the roof. In theory you can insulate a torch-down roof, but I'd recommend against it. (Iso board and flamethrowers do not mix.)

[in2herbs]

3. Thank you for the sage advice. Had a storm here during the night and developed three new leaks.