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. 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- by 80-foot rolls.