TL-0011 — Adhesion of Rubberized Asphalt Membranes to PERM-A-BARRIER® Liquid in Air and Vapor Barrier Applications Technical Letter

Adhesion of flexible flashings (such as PERM-A-BARRIER® Wall Flashing and PERM-A-BARRIER® Detail Membrane) to PERM-A-BARRIER® Liquid may be reduced if the PERM-A-BARRIER® Liquid surface develops a chalky film. This film may be the result of improper spray gun set-up or the result of extended exposure to heat and moisture. This technical letter provides guidance for adhering flexible flashings to PERM-A-BARRIER® Liquid that has developed a chalky surface. Note: The procedures in this technical letter can also be used if the PERM-A-BARRIER® Liquid surface has been subjected to surface contamination by general construction dirt and dust.

A chalky film may develop when PERM-A-BARRIER® Liquid is exposed to elevated temperatures (greater than approximately 60°F), and moisture (rain, dew, high humidity) and has been unprotected for more than one day. This film discoloration does not affect the functional performance of the film.

To adhere PERM-A-BARRIER® Wall Membranes and Flashings to PERM-A-BARRIER® Liquid, once this chalky surface has appeared, apply PERM-A-BARRIER® Liquid Part B (for temperatures above 40°F) or BITUTHENE® Primer B2 (for temperatures between 20°F and 50°F) to the area where the flashing will be adhered.

Application Directions

For temperature above 40°F

Material: Use PERM-A-BARRIER® Liquid Part B or PROCOR® Part B
Application: Apply a thin, continuous layer with a paint roller or brush.
Drying Time: Allow Part B to dry for a minimum of one hour (or dry to touch). If the flashing has not been adhered within 3 days, or if contaminated, reapply the primer.
Coverage: 10-12 m2/L (400-500 ft2/gal) To aid in ease of application and increase coverage area, Part B can be diluted to 50% with water.

For temperatures between 20°F and 50°F

Material: Use GCP Applied Technologies BITUTHENE® Primer B2
Application: Apply a thin, continuous layer with a paint roller or brush. See product data sheet for more specific guidance.
Drying Time: Allow the BITUTHENE® Primer B2 to dry for a minimum of one hour (or dry to touch). If the flashing has not been adhered within 3 days, or if contaminated, reapply the primer.
Coverage: 6-8 m2/L (250-350 ft2/gal) Once a primer has been applied and dried, roll the surface of the flexible flashing with a hard surface roller to ensure adequate adhesion. Terminate critical flashing edges with BITUTHENE® Liquid Membrane.

Note: Applying flexible flashings to freshly applied PERM-A-BARRIER® Liquid (approximately one half hour after spraying and no longer than 12 hours after the PERM-A-BARRIER® Liquid application) may eliminate or reduce the need for primer.

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This document is only current as of the last updated date stated below and is valid only for use in the United States. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on www.gcpat.com. Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2018-11-29

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