A. Architect and roofing consultant Harrison McCampbell responds: For a variety of marketing reasons, the bids you receive from local roofing contractors may not reflect national averages. Normally, the cost of a fully adhered EPDM roof should be fairly close to the cost of a modified bitumen roof.
EPDM is a butyl-based rubber treated to withstand UV and direct exposure to the sun. An EPDM roof will probably outlast a modified bitumen roof or any other asphalt-based membrane. Asphalt products contain oil, which evaporates, eventually rendering the carrier dry and brittle. Frequent wet-dry cycles will accelerate that process, especially if...
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