VYCOR® Plus Data Sheet

Self-adhered flashing for windows, doors, and details

Moisture Control is the First Step to Mold Control

Water from both exterior and interior sources is among the worst enemies of building structures. When water enters the wall system and remains there for a long time, it creates a favorable environment for the development of rot, mold and mildew. Proper waterproofing and flashing practices are necessary to ensure high quality, longlasting construction.

The risk of rot and mold is a major concerns for homebuilders, contractors, architects, and homeowners. Repairing rot and mold is very difficult, and extremely costly. Window and door openings, deck-to-wall intersections, foundation sill plates, corners, and other penetration areas are the most common water entry points. A self-adhered flashing membrane, properly integrated with the other elements of the building structure, creates a barrier to water and air infiltration and a drainage plane for water to drain out of the wall.

VYCOR® Plus high performance self-adhered flashing membrane provides premium protection against water and air infiltration in all critical non-roof detail areas. When properly installed, it can reduce the risk of rot and mold development, often associated with costly call-backs.

Product Description

VYCOR® Plus self-adhered flashing is composed of durable, cross-laminated, high-density polyethylene sheet, backed by an aggressive, pressure-sensitive rubberized asphalt adhesive. VYCOR® Plus flashing is available in a range of widths: 4 in. (100 mm), 6 in. (150 mm), 9 in. (225 mm), 12 in. (300 mm) and 18 in. (450 mm) to accommodate a variety of job requirements. RIPCORD® split release on demand feature is included in 6 in. (150 mm), 9 in. (225 mm) and 12 in. (300 mm) wide membranes.

Product Advantages

  • RIPCORD® split release on demand

  • Easier and faster to install correctly

  • Improved product performance

  • Easy to integrate with housewrap and other weather-resistive barriers

  • Reduces the risk of rot and mold development

Features & Benefits

  • RIPCORD® — With the sophistication of construction practices it becomes a must to follow the proper sequencing principles. RIPCORD® split release offers the flexibility to install half the membrane before and the other half after the other building envelope components are installed, i.e. housewrap or felt. Only in this way are the proper installation principles followed.
  • Easy to work with — Membrane installation is fast and easy— simply remove the release paper and press onto the substrate. With VYCOR® Plus flashings allow contractors to flash more windows with better quality.
  • Superior adhesion capabilities — The membrane creates a strong bond to the substrate for long-lasting waterproofing protection.
  • Seals around fasteners — The specially formulated rubberized asphalt adhesive seals around fasteners, allowing no water to penetrate and get to the substrate.
  • Forms water-tight laps — VYCOR® Plus flashing's superior adhesion properties ensure strong laps, even in seams in the flashing.
  • Measurement markings — The membrane surface is clearly marked at 6 in. (150 mm) and 12 in. (300 mm) intervals to facilitate the installation procedure.
  • Highly conformable and flexible — Can accommodate settlement and shrinkage movement.
  • Proven track record — VYCOR® Plus flashing employs the same proven technology as our Grace Ice & Water Shield® —the market leader in self-adhered underlayments for over 35 years.
  • Long-lasting waterproofing protection — The polyethylene film and the specially-formulated rubberized asphalt components create a water and moisture barrier that does not degrade from the effects of the environment.


VYCOR® Plus self-adhered flashing is a unique solution, appropriate for working around a number of detail areas, including, but not limited to:

  • Window and door openings (headers, sills, jambs, thresholds, nailing flanges)
  • Deck-to-wall intersections
  • Inside and outside corners of sheathing
  • Wall-to-wall tie-ins
  • Foundation sill plates
  • Sheathing panel seams
  • Under stucco finishes
  • Masonry walls
  • Other non-roof detail areas


Complies with the requirements of AAMA 711 for self adhered flashing materials.

Product Data

Property Vycor® Plus      
In-Service Temperature - 40°F to 160°F
(- 40°C to 72°C)
Product thickness 25 mil (0.64 mm)      
Carrier film Cross-laminated HDPE    
Adhesive Rubberized asphalt    
Release liner Paper        
Color Black-Grey    
Recommended exposure limit 30 Days      
Roll width(s) 4 in. (100 mm) 6 in. (100 mm) 9 in. (100 mm) 12 in. (100 mm) 18 in. (100 mm)
Roll length(s) 75 ft (22.9 m) 75 ft (22.9 m) 75 ft (22.9 m) 75 ft (22.9 m) 75 ft (22.9 m)
Rolls per carton 18 12 6 6 2
Shipping weight 74 lbs (33 kg) 74 lbs (33 kg) 56 lbs (33 kg) 74 lbs (33 kg) 36 lbs (33 kg)
Cartons per pallet 30 30 30 30 35

Precautions & Limitations

VYCOR® Plus self-adhered flashing is designed for critical NON-ROOF flashing details. The membrane is slippery—DO NOT install on the roof; DO NOT walk on the membrane.

Do not leave the product permanently exposed to sunlight. Maximum recommended exposure time is 30 days. Due to its slight asphaltic odor, apply this product where the membrane is not exposed to interior living space. 

VYCOR® Plus flashing is not compatible with flexible PVC and high concentrations of resin (pitch). Contact window manufacturer for specific application instructions required when using a bituminous-based flashing. Certain metal window applications with integral nail fin may have specific limitations.

Some solvents in certain caulking may be incompatible with the adhesive in VYCOR® Plus flashing.

For more information, check with your local GCP Applied Technologies technical sales representative.

Application Instructions

Surface Preparation

Apply VYCOR® Plus flashing in fair weather when the air, surface and membrane are at temperatures of 25°F (-4°C) or higher. After precipitation, allow a minimum of 24 hours for drying before installing the flashing.

Install directly onto a clean and dry surface. Some compatible substrates include wood, plywood, oriented strand board, metal, concrete and masonry. 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, prime wood composition and gypsum sheathing also with PERM-A-BARRIER® WB Primer. The coverage rate for PERM-A-BARRIER® WB Primer is 250–350 ft2/gal (6–8 m2/L). Allow primer to dry completely, approximately 1 hour depending on weather conditions, before application of flashing.


Membrane Installation

Using the 6 in. (150 mm) and 12 in. (300 mm) measurement markings, cut the membrane to the desired length. Peel back the release paper to expose the adhesive. Align the membrane and press into place with heavy hand pressure.

Laps must be a minimum of 3 in. (75 mm). Mechanically fasten the membrane at all vertical terminations. Use only smooth shank fasteners.

Consistent with good construction practice, install the membrane such that all laps shed water (following the shingle principle). The top membrane layer should go over the bottom layer. Always work from the low point to the high point. When needed, use RIPCORD® split release on demand to split the release paper and adhere half of the membrane, while leaving the other half with the paper on. This is required when flashing a window sill before the housewrap/ weather resistive barrier is installed.

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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® enV® , 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.

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GCP Applied Technologies Inc., 2325 Lakeview Parkway, Suite 400, Alpharetta, GA 30009, USA
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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: 2023-12-08