PERM-A-BARRIER® Detail Membrane Data Sheet

Self-adhesive, rubberized asphalt/polyethylene detail membrane for air and vapor barrier applications

Product Description

PERM-A-BARRIER® Detail Membrane is ideal for protecting and sealing critical areas of the building superstructure from the damaging effects of the elements. By minimizing air and water vapor flow through the building exterior at transition areas, PERM-A-BARRIER® Detail Membrane:

  • Seals transition and detail areas to provide a continuous air barrier
  • Prevents premature deterioration of the building envelope

Product Advantages

  • Fully bonded - transmits wind loads directly to the substrate
  • Waterproof and impermeable to moisture - impermeable to the passage of liquid water and water vapor
  • Air tight - exceeds CCMC requirements for air barrier membranes, complies with Massachusetts State Energy Code
  • Cross laminated film - provides dimensional stability, high tear strength, puncture and impact resistance
  • Cold applied - no flame hazard; self-adhesive overlaps ensure continuity
  • Flexible - accommodates minor settlement and shrinkage movement
  • Controlled thickness - factory made sheet ensures constant, non-variable site application
  • Aggressive, conformable adhesive - allows self-sealing around mechanical fasteners 
  • Wide application window - PERM-A-BARRIER® Detail Membrane surface and ambient temperatures at 25°F (-4°C) and above

System Components

  • PERM-A-BARRIER® Detail Membrane - fully adhered flashing for protecting and sealing critical detail areas
  • PERM-A-BARRIER® WB Primer - high tack, water-based primer for use with PERM-A-BARRIER® Detail Membrane on cementitious and exterior gypsum wallboards
  • BITUTHENE® Primer B2 LVC - low VOC primer used to prime green concrete or damp surfaces
  • PERM-A-BARRIER® Universal Flashing & Sealant - one part moisture curing, STPE sealant for sealing penetrations, terminations, brick ties, final terminations & flashing application.
  • BITUTHENE® Mastic Trowel Grade - rubberized asphalt mastic for sealing patches, terminations, brick ties, etc.
  • BITUTHENE® Liquid Membrane - two component, trowel grade, asphalt modified urethane for sealing patches, terminations, brick ties, etc.



PERM-A-BARRIER® products must be handled properly. Vapors from the mastic and solvent-based primer are harmful and flammable. For these products, the best available information on safe handling, storage, personal protection, health and environmental considerations has been gathered. Refer to product label and SDS (Safety Data Sheet) before use. All users should acquaint themselves with this information prior to working with the material. Carefully read detailed precaution statements on the product labels and SDS before use. SDSs can be obtained from our web site at or by contacting us toll free at 866-333-3SBM (3726).

Surface Preparation

Surface must be smooth, clean, dry and free of voids, spalled areas, loose aggregate, loose nails, sharp protrusions or other matter that will hinder the adhesion or regularity of the wall membrane installation. Clean loose dust or dirt from the surface to which the detail membrane is to be applied by wiping with a clean, dry cloth or brush.

If the substrate is damp, allow to dry or use BITUTHENE® Primer B2 LVC to prepare the area to receive the membrane. DO NOT apply any primer to PERM-A-BARRIER® Detail Membrane.


PERM-A-BARRIER® Detail Membrane may only be applied in dry weather when air and surface temperatures are above 25°F (-4°C).


Priming - PERM-A-BARRIER® Primer® Plus and PERM-A-BARRIER® WB Primer are water-based primers which impart an aggressive, high tack finish on the treated substrate. They are packaged ready to use and are specifically designed to facilitate tenacious adhesion of PERM-A-BARRIER® Detail Membrane to various substrates including glass-mat faced gypsum sheathing. Refer to Technical Letter 2, Substrate Preparation for Application of PERM-A-BARRIER® Products to Glass-Mat Faced Gypsum Sheathing for priming requirements on specific glass-mat faced sheathing products.

Detail Membrane Application - Pre-cut PERM-A-BARRIER® Detail Membrane to easily handled lengths. Peel release paper from roll to expose rubberized asphalt and carefully position tape against substrate. Press firmly into place with a steel hand roller or the back of a utility knife as soon as possible, fully adhering the tape to the substrate to prevent water from migrating under the PERM-A-BARRIER® Detail Membrane. Overlap adjacent pieces 2 in. (51 mm) and roll overlap with a steel hand roller.

When applying PERM-A-BARRIER® Detail Membrane to PERM-A-BARRIER® Wall Membranes and PERM-A-BARRIER® Wall Flashing - Apply a bead of Universal Flashing & Sealant, BITUTHENE® Mastic or BITUTHENE® Liquid Membrane along top edges, cuts, penetrations, all laps and seams on horizontal surfaces (e.g. sill plates), critical areas and as shown in GCP detail drawings, and trowel into place.

When applying PERM-A-BARRIER® Detail Membrane to PERM-A-BARRIER® Liquid, PERM-A-BARRIER® VP, PERM-A-BARRIER® VP Low Temp or PERM-A-BARRIER® VPO - Apply a bead of Universal Flashing & Sealant or BITUTHENE® Liquid Membrane along top edges, cuts, penetrations, all laps and seams on horizontal surfaces (e.g. sill plates), critical areas and as shown in GCP detail drawings, and trowel into place. If PERM-A-BARRIER® Liquid is more than 7 days old, priming may be necessary. Refer to Technical Letter 11 for more information.

No reglet is necessary when installing PERM-A-BARRIER® Detail Membrane to vertical surfaces. Complete installation instructions and details are available upon request.

If wrinkles develop, carefully cut out affected area and replace in similar procedure outlined above. The repair piece must be pressed into place with a hand roller as soon as possible to ensure continuous and intimate contact with the substrate.

All non water shedding edges must be sealed with Universal Flashing & Sealant, BITUTHENE® Liquid Membrane or BITUTHENE® Mastic.

Membrane Protection

PERM-A-BARRIER® Detail Membrane must be protected from damage by other trades or construction materials.

Storage and Handling Information

All materials must be protected from rain and physical damage. Pallets of PERM-A-BARRIER® Wall Membrane must not be double stacked on the job site. Provide cover on top and all sides, allowing for adequate ventilation. Store membrane where temperatures will not exceed 90°F (32°C) for extended periods. All products must be stored in a dry area away from high heat, flames or sparks. Store only as much material at point of use as is required for each day’s work.


PERM-A-BARRIER® Membrane systems must not be applied in areas where they will be permanently exposed to UV light and must be covered within a reasonable amount of time, not to exceed 60 days. Refer to Technical Letter 19, Exposure Guidelines for PERM-A-BARRIER® Self-Adhered Membranes.

PERM-A-BARRIER® Detail Membrane and all other PERM-A-BARRIER®  self-adhered membranes should not be applied over Universal Flashing & Sealant.


PERM-A-BARRIER® products are warranted to be free of defects in manufacture for a period of 5 years. Material will be provided at no charge to replace any defective product.

Technical Service

Support is provided by full-time technically trained GCP field sales representatives and technical service personnel, backed by a central research and development technical services staff.


  Unit of Sale Approximate Coverage Weight Palletization
PERM-A-BARRIER® Detail Membrane        
6 in. (152 mm)
9 in. (225 mm)
12 in. (305 mm)
6 rolls
4 rolls
3 rolls
75 linear ft per roll
75 linear ft per roll
75 linear ft per roll
11 lbs/roll
16 lbs/roll
22 lbs/roll
25 cartons (150 rolls) per pallet
25 cartons (100 rolls) per pallet
25 cartons (75 rolls) per pallet
BITUTHENE® Mastic - 5 gal pail 1 pail approx. 120 ft2 at 60 mils 54 lbs/pail 36 pails per pallet
BITUTHENE® Mastic - 30 oz tube 12 tubes approx. 30 linear ft x 1/4 in. bead 32 lbs/carton 72 cartons (864 tubes) per pallet
PERM-A-BARRIER® Universal Flashing & Sealant - 29 oz. Cartridge 1 cartridge approx. 30 linear ft x 1/4 1/4 in. bead 29 oz. cartridge 10 cartridges/ carton
42 cartons/ pallet
BITUTHENE® Liquid Membrane - 1.5 gal pail 1 pail approx. 200 Linear ft/gal @ 1” wide x 90 mils. 16 lbs/pail 100 pails per pallet
BITUTHENE® Liquid Membrane - 4 gal pail 1 pail approx. 200 Linear ft/gal @ 1” wide x 90 mils. 44 lbs/pail 24 pails per pallet
PERM-A-BARRIER® WB Primer - 5 gal pail 1 pail 250–350 ft2/gal (6–8 m2/L) 45 lbs 32 pails per pallet
BITUTHENE® Primer B2 LVC - 5 gal pail 1 pail 325–425 ft2/gal (7.5–10 m2/L) 44 lbs/pail 48 pails per pallet

Physical Properties

  PERM-A-BARRIER® Detail Membrane Test Method
Thickness 3/64 in. (1 mm) ASTM D3767 method A
Minimum tensile strength, membranes 400 psi (2.8 MPa) ASTM D412 die C modified
Minimum tensile strength, film 5000 psi (34.5 MPa) ASTM D412 die C modified
Minimum elongation, to failure of rubberized asphalt 200% ASTM D412 die C modified
Pliability, at 180° bend over 1 in. (25 mm) mandre Pass at -25 °F (-32 °C) ASTM D1970
Crack cycling, 1/8 in. (3.2 mm) at -25 °F (-32 °C) Unaffected ASTM C836
Minimum puncture resistance, membrane 40 lbs (178 N) ASTM E154
Lap peel adhesion at minimum application temperature 4 lbs/in. (700 N/m width) ASTM D1876 modified
Maximum permeance to water vapor transmission 0.05 perms/(Pa.s.m2) (2.9 ng) ASTM E96 method B
Air permeance1 0.0002 cf/min/ft2 (<0.001 L/s/m2) ASTM E2178
Air permeance of in-place membrane2 No change in air permeance value ASTM E330
Water absorption (weight gain at 24 hours) 0.1% ASTM D570

1. Air permeance measured at a pressure differential of 1/64 in. (68 Pa) Hg.
2. Air permeance measured at a pressure differential of 1/64 in. (68 Pa) Hg after wall being subjected to a negative 57/64 in. (3014 Pa) Hg pressure difference for 10 seconds. | 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.

BITUTHENE and PERM-A-BARRIER 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., 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