TL-0019 — Exposure Guidelines for PERM-A-BARRIER® Technical Letter

PERM-A-BARRIER® (including PERM-A-BARRIER® Wall Membrane, PERM-A-BARRIER® Aluminum Wall Membrane, PERM-A-BARRIER® Wall Flashing, PERM-A-BARRIER® Detail Membrane, PERM-A-BARRIER® Aluminum Flashing, PERM-A-BARRIER® NPS and PERM-A-BARRIER® VPS30, PERM-A-BARRIER NPL10, PERM-A-BARRIER VPL, & PERM-A-BARRIER VPL50 RS UV STABLE) are not meant to be left permanently exposed to the sun. In general, the air barriers should be covered with the final wall covering as soon as possible. However, GCP Applied Technologies (GCP) PERM-A-BARRIER® products may be left exposed (as described in the general exposure guidelines below) if necessary, to accommodate construction scheduling or weather problems.

PERM-A-BARRIER® Self-Adhered Membranes Maximum Exposure Guidelines
Wall Membrane 3 Months
Aluminum Wall Membrane 1 Year
Wall Flashing 3 Months
Detail Membrane 3 Months
Aluminum Flashing 1 Year
NPS 1 Year
NPS Detail Membrane 1 Year
VPS 30 9 Months
NPL 10 2 Months
VPL 6 Months

During the time period the product is left exposed there are two primary factors at work on the membrane: heat and ultraviolet (UV) radiation. Heat will not likely affect the performance but there may be some changes in appearance depending on the climate and length of exposure. UV radiation will not affect the membrane in any significant way during its maximum exposure limit.

After the maximum exposure period, it is normal for the self-adhered membranes to appear slightly wrinkled. There may be a small amount of curling at the edges of the membrane as well. None of these issues will affect the performance of PERM-A-BARRIER® products once covered.

Before covering the membrane after a long exposure, it should be inspected to ensure that any wrinkling or other movement that has taken place has not affected any of the lap areas. If a wrinkle forms that extends to the edge of a lap, it must be cut, pressed down, and patched before the wall is covered. Any curling at the edges or corners must be cut and patched if the affected area is more than 1/2 inch (13 mm) wide.

Use a patch of membrane extending past the damaged area 3 inches (75mm) in all directions and seal any non-watershedding edges with PERM-A-BARRIER® S100, PERM-A-BARRIER® Universal Flashing & Sealant, or BITUTHENE® Liquid Membrane. | North America Customer Service: +1 (877) 423 6491

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation or suggestion is intended for any use that would infringe any patent, copyright or other third-party right.

PERM-A-BARRIER, BITUTHENE, and RIPCORD are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies, Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

© Copyright 2018 GCP Applied Technologies, Inc. All rights reserved.

GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140, USA

GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6

GCP Applied Technologies Inc., 2325 Lakeview Parkway, Suite 400, Alpharetta, GA 30009, USA
GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6
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 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: 2023-06-28