Benjamin Obdyke is addressing an increasing problem of moisture buildup under the roof with the introduction of VaporDry SA, one of the industry’s first self-adhered, vapor-permeable roofing membranes. 

“When warm, humid air rises up into the attic, a vapor-closed membrane, such self-adhered eave barriers or synthetic underlayments, will cause that moisture to become trapped and build up, particularly as homes have gotten tighter,” said Kaylen Handly, Technical Innovation Manager for Benjamin Obdyke. “As a vapor-permeable membrane, VaporDry SA allows that moisture to migrate, increasing drying potential to reduce the likelihood of long-term issues that lead to rot at the ridge line and premature roof failure.”

VaporDry SA features a continuous acrylic adhesive that is repositionable during installation and self-seals around roofing fasteners, allowing the membrane to serve as an air-control layer in addition to a moisture-control layer. The acrylic adhesive also is approved for 250-degree F service temperatures, so it is appropriate for use under metal roofs. The membrane’s tri-laminate structure is durable under foot traffic, and a reinforcement scrim in the adhesive provides for more tensile strength. The surface is slip-resistant and features printed overlay guides for easier installation. 

VaporDry SA is suitable for use with all roofing types, including wood, metal, composite, and asphalt, with a pitch of 3:12 or greater. For maximum drying potential, install VaporDry SA as a system with Cedar Breather Ventilated Roof Mat for wood, metal, and cold roof applications. VaporDry SA meets ASTM D1970 testing standards for nail sealability and ICC-ES AC48 for Self-Adhered Underlayments to be used as an ice barrier, and it can be left exposed for 120 days. It comes in 4.75-foot-by-80-foot rolls.

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