4” seaming tape for roof decking

Product Description

ROOF DETAIL TAPE is a premier 4” tape based on the GRACE ICE & WATER SHIELD®  roofing underlayment technology. The tape complies with ASTM D1970 and the Connecticut State Building Code. It is composed of two waterproofing materials—an aggressive rubberized asphalt adhesive backed by a high performance waterproofing film. The rubberized asphalt surface is backed with a release paper that protects its adhesive quality. During application, the release paper is easily removed, allowing the rubberized asphalt to bond tightly to the roof deck, the tape itself and GRACE ICE & WATER SHIELD® roofing underlayments.

Product Advantages

  • Complies with ASTM D1970 and the Connecticut State Building Code
  • Easy to handle and apply
  • Bonds firmly to the roof deck and seals to itself
  • Seals around fasteners
  • Membrane will not crack, dry out or rot
  • Protects under all standard sloped roof coverings
  • Slip resistant surface
  • Reroofable
  • Proven track record

Features & Benefits

  • Complies with ASTM D1970 and the Connecticut State Building Code – 4” ROOF DETAIL TAPE is made up of a self-adhering polymer-modified bitumen membrane, and complies with ASTM D1970, ensuring compliance with the Connecticut State Building Code.
  • Easy to handle and apply—The self-adhesive tape bonds firmly to the substrate and seals to itself without heat or special adhesives. 
  • Seals around fasteners—The rubberized asphalt layer in ROOF DETAIL TAPE seals around roofing fasteners, resisting leakage caused by water back-up behind ice dams, or from wind- driven rain.
  • Tape will not crack, dry out or rot—ROOF DETAIL TAPE resists attacks from fungus and bacteria; maintains its integrity for long lasting protection.
  • Protects under all standard sloped roof coverings— ROOF DETAIL TAPE protects under slate, tile, cedar shakes or metal, as well as under conventional asphalt shingles.
  • Slip resistant surface—ROOF DETAIL TAPE has a slip resistant embossed surface to maximize traction and safety for applicators.
  • Reroofable—ROOF DETAIL TAPE will not adhere to the underside of the exposed roof covering. 
  • Proven track record—ROOF DETAIL TAPE is based on GRACE ICE & WATER SHIELD® underlayment, the name brand in roofing underlayments with over 30 years of protecting roofs from ice dams and wind-driven rain.
  • Technical support—ROOF DETAIL TAPE is backed by a team of technical support personnel that help ensure every application goes smoothly.

Guidelines for Use

ROOF DETAIL TAPE is used to seam the joints in roof decking and also as a flashing to provide resistance against water infiltration at trouble-prone roof detail areas. Local building codes should be consulted for specific requirements.

Installation Procedure

Surface Preparation

Install ROOF DETAIL TAPE directly on a clean, dry, continuous structural substrate. Some suitable substrates are plywood, wood composition, metal, concrete or gypsum sheathing. For all other substrates, contact your GCP representative. Remove dust, dirt, loose nails and old roofing materials. Protrusions from the substrate area must be removed. Substrates shall have no damaged or unsupported areas, or voids. Repair substrate before installing the membrane.


Prime concrete, masonry, DensGlass Gold®  and DensDeck®  surfaces with PERM-A-BARRIER®  WB primer. Prime wood composition and gypsum sheathing with PERM-A-BARRIER®  WB primer if adhesion is found to be marginal (refer to Technical Letter 12, Use on Oriented Strand Board (OSB) Roof Sheathing). Apply PERM-A-BARRIER®  WB primer at a rate of 250–350 ft2/gal (6–8 m2/L). Priming is not required for other suitable surfaces provided that they are clean and dry.

Safety and Handling

Read and understand the product label and Safety Data Sheet (SDS) for each system component. All users should acquaint themselves with this information prior to working with the products and follow the precautionary statements. SDSs can be obtained from our web site at or by contacting GCP toll free at 1-866-333-3SBM (3726).

Precaution & Limitations

  • Slippery when wet or covered by frost.
  • Consistent with good roofing practice, always wear fall protection when working on a roof deck.
  • Release liners are slippery. Remove from work area immediately after membrane application.
  • Do not leave permanently exposed to sunlight. Cover within 30 days.
  • Do not fold over the roof edge unless the edge is protected by a drip edge, gutter or other flashing material.
  • Do not install on chamfered edges of wood plank.
  • If the tape shows any holes, fishmouths, tears or damage, cut out damaged area and discard. Seals around nails or fasteners.
  • Fully adheres to decks, resisting leaks from wind-driven rain or water backup due to ice dams. If fasteners are removed leaving holes in the tape, they must be patched. The membrane may not self-seal open fastener penetrations.
  • Do not install fasteners through the membrane over unsupported membrane areas of the structural deck, such as over the joints between adjacent structural panels.
  • Due to its slight asphaltic odor, do not apply where membrane is exposed to interior living spaces. Refer to product literature for more complete information.
  • Not compatible with EPDM or TPO.
  • Not compatible with polysulfides, uncured neoprene, wood substrates with high concentrations of resin (pitch), or flexible PVC. ROOF DETAIL TAPE is generally compatible with window and skylight flanges; for more information, refer to Technical Letter 5.
  • Do not use in the desert southwest U.S.
  • Do not use under copper, COR-TEN®  or zinc metal roofs in high altitudes.


Roll Length 50 ft (15.2 m)
Roll Width 4 in. (101.6 mm)
Roll Size 16.7 ft2 (1.5 m2)
Packaging 18 individually wrapped rolls in corrugated
Roll Weight 4.2 lbs (1.9 kg)
Rolls per carton 18
Cartons per pallet 30

Code Compliance

ROOF DETAIL TAPE meets the following standards:

  • Underwriters Laboratories Inc. Class A fire classification under fiber-glass shingles and Class C under organic felt shingles (per ASTM E108/UL 790)
  • International Conference of Building Officials (ICBO-ES) Report No. 3997
  • Southern Building Code Congress International (SBCCI PST & ESI) Report No. 94133C
  • Building Officials and Code Administrators (BOCA-ES) Evaluation Report No. 94-33
  • Miami-Dade County NOA 09-0107.08.
  • City of Los Angeles RR 25330

Performance Properties

Property Typical Value Test Method
Color Grey-black  
Thickness, membrane 40 mil (1.02 mm) ASTM D3727 method A
Tensile strength, membrane 250 psi (1720 kN/m2) ASTM
D412 (Die C modified)
Elongation, membrane 250% ASTM D412 (Die C modified)
Low temperature flexibility Unaffected @ -20°F (-29°C) ASTM D1970
Adhesion to plywood 3.0 lbs/inc. width (525 N/m) ASTM D903
Permeance (max) 0.05 Perms (2.9 ng/m2s Pa) ASTM E96
Material weight installed (max) 0.3 lb/ft2 (1.3 kg/m2) ASTM D461 | 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.

GRACE ICE & WATER, GRACE ULTRA, GCP granular underlayment, PERM-A-BARRIER, and RIPCORD are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. COR-TEN is a trademark registered in the United States and/or other countries, of United States Steel Corporation. DensGlass Gold and DensDeck are registered trademark of Georgia-Pacific Corporation. 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