Water Migration Resistance
When fasteners penetrate roofing or waterproofing products as a planned part of installation, it is expected in some cases that the product will resist water migration at the point of penetration. A new ASTM International standard, D7349, Test Method for Determining the Capability of Roofing and Waterproofing Materials to Seal Around Fasteners, addresses this situation. D7349 was developed by Subcommittee D08.02 on Prepared Roofings, Shingles and Siding Materials, part of ASTM International Committee D08 on Roofing and Waterproofing.
Aaron Phillips, technical systems specialist, TAMKO Building Products Inc., and D08.02 member, says that until the approval of D7349, the only standard that measured this type of water migration resistance was D1970, Specification for Self-Adhering Polymer Modified Bituminous Sheet Materials Used as Steep Roofing Underlayment for Ice Dam Protection. “That method is specifically directed toward one class of materials,” says Phillips. “The test parameters used for ice dam membranes may not be appropriate for other product types.”
Phillips says D7349 provides a more broadly applicable test method for these situations. “Unlike D1970, which is intended to evaluate a single end use, D7349 is adaptable for evaluation of a variety of asphalt-based products and end uses,” says Phillips. “This flexibility is present in the form of protocols that establish test parameters associated with a specific end use.” New protocols can be added to the test method as user needs arise.
Technical Information: Aaron Phillips, TAMKO Building Products Inc., Joplin, Mo.
Phone: 417-624-6644, ext. 2295
Staff: Joseph Hugo