TL-0004 — Surface Preparation Technical Letter

VYCOR® Self-Adhered Flashings (VYCOR® Plus, VYCOR® V40, VYCOR® Aluminum, VYCOR® PRO and VYCOR® Deck Protector®) are to be applied directly to a clean and dry surface. Some suitable substrates include wood, pressure treated wood, plywood, wood composition, oriented strand board (OSB), metal, Integral WRB Sheathing (Such as Huber Zip System®), vinyl, concrete, masonry and gypsum sheathing. For additional information, refer to product literature and Technical Letter 1, Chemical Compatibility with Other Building Materials, located in the product manual and on our web sites.

Remove dust, dirt, and loose nails. Protrusions must be removed. Surfaces shall have no voids, damaged, or unsupported areas. Repair surfaces before installing the membrane.

Priming is generally not required for most substrates provided they are clean and dry. However, on concrete, masonry and DensGlass Gold®, apply PERM-A-BARRIER® WB Primer. If adhesion is found to be marginal, also prime wood composition and gypsum sheathing with PERM-A-BARRIER WB Primer. The coverage rate for PERM-A-BARRIER WB Primer is 250–350 ft2/gal (6–8 m2/L).

Substrate VYCOR®  Pro Other VYCOR® Flashings
Pressure Treated Wood
Wood Composition
Oriented Strand Board (OSB)
DensGlass Gold
Gypsum Sheathing
Integral WRB Sheathing

Additional Substrate Preparation (Priming)

⚫ Priming substrate is recommended

⭕ Prime substrate if adhesion is determined to be marginal

⦻ Priming is not likely required

For any building materials not listed, please contact your local GCP technical sales representative. | North America Customer Service: 1 877-4AD-MIX1 (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.

VYCOR, VYCOR Deck Protector, and PERM-A-BARRIER are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc.

DensGlass Gold is a registered trademark of Georgia-Pacific Corporation. Huber Zip System is a registered trademark of Huber Engineered Woods, LLC. 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.



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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: 2022-05-09