PERM-A-BARRIER® WB Primer Data Sheet

Water-based primer for use with Perm-A-Barrier Flashings, Detail Membrane and Wall Membrane

Product Description

PERM-A-BARRIER® WB Primer is a water-based primer which imparts an aggressive, high tack finish on the treated substrate. It is specifically designed to facilitate tenacious adhesion of PERM-A-BARRIER® Flashings, PERM-A-BARRIER® Detail Membrane and PERM-A-BARRIER® Wall Membrane to various substrate 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.

Product Advantages

  • Excellent adhesion—bonds to substrate and binds dust
  • Aggressive tack—provides a tenacious bond to difficult substrates such as DensGlass Gold and other glass faced wall boards
  • Fast drying—increased flexibility for application schedule
  • Fast and easy application—by brush or roller
  • VOC compliant—water-based, contains no hazardous or flammable solvents
  • Low odor—no noxious fumes


PERM-A-BARRIER® WB Primer can be used at 25 °F (-4 °C) or above. It will freeze at 21 °F (-7 °C) and can no longer be used after it freezes.


PERM-A-BARRIER® WB Primer is available in 1 gallon jugs and 5 gallon plastic pails.


Safety, Storage and Handling Information

PERM-A-BARRIER® WB Primer is nonflammable. SDS (Safety Data Sheet) are available at and users should acquaint themselves with this information. Carefully read detailed precaution statements on product labels and the SDS before use.

Store above freezing 32 °F (0 °C).

The VOC (Volatile Organic Compound) content is 10 g/L and it meets the U.S. EPA Volatile Organic Compound Emission Standard for Architectural Coatings.

Architectural and industrial maintenance regulations limit the VOC content in products classified as architectural coatings. Refer to Technical Letters at for the most current list of allowable limits.


Apply primer in dry weather with ambient and substrate temperatures above 25 °F (-4 °C). Surface must be dry and clean.

Surface Preparation

All surfaces must be free from frost, dirt, grease, oil or other contaminants. Failure to remove excessive dust may result in compromised adhesion of the membrane.

In cooler or humid conditions, priming may be done in advance. If primed surface is exposed for more than 7 days, or if significant dust or dirt accumulates on the surface, re-prime with a thin coat of PERM-A-BARRIER® WB Primer.

Roller Technique

Synthetic, 1/2 in. (13 mm), nap rollers have been found to be very successful for the application of PERM-A-BARRIER® WB Primer. A moderately thick coating should be applied and rolled out evenly (see coverage below). A properly applied coating will have uniform coverage and leave a tacky finish to the surface when dry.


250–350 ft2 /gal (6.0–8.0 m2 /L)

Drying Time

To be effective, the PERM-A-BARRIER® WB Primer needs to fully dry. Drying time of the material is dependent upon many factors including temperature, humidity, wind, sunlight and coverage rate. The drying time could vary from as little as 15 min. (warm and windy) to 3 hours (cold and no wind), depending upon the weather condition. The following are guidelines for dry time at various temperatures:

  • 90 °F (32 °C) or greater: 45 min.–1 hr
  • 50 °F (10 °C) to 90 °F (32 °C): 1–3 hrs
  • Less than 50 °F (10 °C): 3 hrs +

 The product is packaged “ready to use.” Do not use any substance to thin this product. | 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 is a trademark, 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