G-Tape 3035BK Deck Joist Tape & Waterproof Flashing Tape – 2", 3" & 4" x 65'

Nichigo G-Tape 3035BK is a professional-grade waterproof deck joist tape and self-adhering flashing tape designed to protect deck framing, joists, beams, rafters, ledger areas, housewrap seams, wall boards, windows, and other exterior construction details from prolonged exposure to rain and moisture.

Designed for permanent exterior applications, G-Tape 3035BK combines a strong acrylic adhesive with a waterproof, highly weather-resistant black backing. Its linerless construction makes installation fast and simple: pull the tape from the roll, tear it straight by hand, press it firmly onto the surface, and move to the next joist or framing member. There is no release paper to peel off, collect, or clean up.

For professional deck builders, remodelers, carpenters, and contractors, 3035BK is an excellent choice for protecting the top of deck joists, beams, rafters, and other wood framing before decking is installed. By creating a waterproof barrier over vulnerable horizontal surfaces, joist flashing tape helps reduce repeated water exposure around the framing and fastener locations where moisture can contribute to premature deterioration.

G-Tape 3035BK is available in 2", 3", and 4" widths, with each roll measuring 65 feet long. The different widths make it easy to choose the right deck flashing tape for standard joists, wider beams, ledger areas, window flashing, housewrap seams, and other exterior construction applications.

Professional Deck Joist Protection Tape

The framing underneath a deck is difficult and expensive to repair once the finished decking has been installed. Although pressure-treated lumber is designed for exterior use, the tops of joists and beams can still experience repeated moisture exposure from rain, snow, irrigation, and water passing through the spaces between deck boards.

Applying G-Tape 3035BK deck joist protection tape before installing the decking creates a waterproof barrier across the top of the framing. This helps keep water from sitting directly on the wood and provides an additional layer of protection in areas that may remain damp after the deck surface itself has dried.

For contractors searching for a deck joist tape, joist flashing tape, deck beam tape, black joist tape, waterproof deck tape, or deck framing protection tape, G-Tape 3035BK provides a lightweight, easy-to-install solution built specifically for exterior construction.

Excellent for Deck Joists, Beams & Rafters

G-Tape 3035BK works well anywhere exterior wood framing needs additional moisture protection. Common applications include the tops of deck joists, built-up beams, support framing, outdoor rafters, rim framing, blocking, and other horizontal or exposed framing members.

G-Tape specifically identifies 3035BK for waterproofing outdoor deck rafters, making it an excellent choice for deck and exterior framing applications where long-term weather resistance is important.

The tape's thin 8.3 mil profile protects the framing without adding the bulk associated with some heavier flashing membranes, allowing decking to sit cleanly over the protected joists.

Deck Beam & Ledger Protection

Larger structural members can collect substantial amounts of water where multiple boards meet or where horizontal surfaces are exposed beneath the deck.

The wider 3" and 4" G-Tape 3035BK rolls are especially useful when additional coverage is needed on deck beams, wider framing members, ledger areas, rim boards, and other exterior construction details.

Choose a tape width that adequately covers the top of the framing and provides the desired coverage around the edges. Properly installed flashing tape can help direct water away from vulnerable wood surfaces instead of allowing moisture to repeatedly soak into the same location.

Waterproof Deck Flashing Tape

G-Tape 3035BK is waterproof and engineered for prolonged exposure to outdoor conditions. Its black backing uses a highly UV-resistant substrate, allowing it to maintain performance through demanding weather exposure during construction and service.

This makes 3035BK an excellent waterproof flashing tape for deck construction, exterior framing, fenestration work, window installations, housewrap, insulation, and wall-board seams.

Rather than using a general-purpose repair tape in a permanent exterior application, contractors can use a flashing product specifically designed around waterproofing, weather resistance, and permanent adhesion.

Linerless Joist Tape Makes Deck Installation Faster

One of the biggest advantages of G-Tape 3035BK is its linerless design.

Traditional flashing tapes often require installers to peel away a release liner while trying to keep the tape aligned. On a large deck with dozens of joists, that extra step creates waste and slows down the installation.

G-Tape 3035BK has no release liner. Simply unroll the tape, position it over the framing, tear it by hand, press it firmly into place, and continue down the deck.

There is no pile of backing paper blowing around the jobsite, and no knife or scissors are required for normal straight cuts.

Tears Straight by Hand

G-Tape 3035BK is engineered to tear straight by hand. For professional deck builders installing hundreds of feet of joist protection tape, this can make a noticeable difference in installation speed.

Instead of setting down the tape, reaching for a utility knife, making the cut, and repeating the process for every framing member, the installer can tear off each section quickly and move directly to the next joist.

Permanent Acrylic Adhesive for Exterior Construction

The 3035BK uses a permanent acrylic adhesive designed for strong initial tack and long-term exterior performance.

The tape adheres well to rough construction surfaces when they are properly prepared and provides the strong bond needed for deck framing, housewrap seams, wall boards, insulation, and window flashing applications.

For best adhesion, install G-Tape 3035BK on a clean, dry surface and press the tape firmly against the substrate.

Highly UV & Weather Resistant

Deck construction does not always happen under perfect conditions. Framing and flashing materials may remain exposed before the decking, siding, windows, or exterior finishes are completed.

G-Tape 3035BK uses a highly UV-resistant black substrate and is engineered to maintain performance after prolonged exposure to sunlight and rain.

Its broad temperature use range also makes it suitable for exterior construction in both hot and cold climates.

Window & Door Flashing Tape

Although 3035BK is an excellent deck joist tape, it was originally engineered as a professional self-adhering flashing tape for exterior wall fenestration.

It can be used for seaming and flashing around window frames and other exterior openings where a waterproof, permanent flashing tape is required.

G-Tape 3035BK meets AAMA 711-13 Type A without primer, Level 3, and AC148 performance requirements, making it much more than a simple general-purpose construction tape.

Housewrap & Exterior Framing Tape

G-Tape also recommends 3035BK for seaming and splicing insulation sheets, housewrap, and wall boards.

This gives contractors one versatile exterior flashing product that can be used for deck framing protection, housewrap seams, insulation, exterior wall systems, and window flashing.

For builders searching for housewrap seam tape, exterior framing tape, waterproof construction tape, wall flashing tape, or permanent exterior tape, G-Tape 3035BK provides strong adhesion with excellent resistance to rain, UV exposure, and temperature changes.

Key Features

Waterproof Deck Joist Tape

Creates a waterproof protective layer over joists, beams, rafters, and other exterior framing members exposed to repeated moisture.

Permanent Self-Adhering Flashing Tape

Strong permanent acrylic adhesive provides dependable bonding for exterior construction and flashing applications.

Linerless Installation

No release paper means faster installation, less jobsite waste, and no backing liner to peel away on every section of tape.

Hand Tearable

Tears straight by hand so installers can work quickly without constantly reaching for a utility knife or scissors.

Waterproof

Designed for exterior applications where protection from rain and moisture is critical.

High UV Resistance

Black UV-resistant backing helps the tape maintain performance during prolonged exposure to sunlight and outdoor weather.

Strong Adhesion on Rough Surfaces

High initial tack and strong permanent adhesion make 3035BK well suited for common construction substrates when installed on clean, dry surfaces.

Lightweight Construction

G-Tape states that 3035BK is approximately 50% to 70% lighter than conventional window flashing tape, making large rolls easier to handle during installation.

Scrap-Less Adhesive Design

If adhesive surfaces accidentally contact each other, they can be separated without immediately destroying the adhesive, helping reduce wasted tape on the jobsite.

All-Weather Performance

Designed for use across a broad temperature range, from approximately -40°F to 200°F.

Recommended Applications

• Deck joist protection
• Deck joist flashing
• Deck beam protection
• Deck framing waterproofing
• Outdoor deck rafters
• Ledger areas
• Rim framing
• Exterior wood framing
• Pressure-treated deck framing protection
• Housewrap seams
• Insulation sheet seams
• Wall-board seams
• Window flashing
• Window-frame seaming
• Exterior fenestration
• General waterproof exterior construction

Available Sizes

2" x 65' G-Tape 3035BK

Part Number: 3035BK-GT-2-65
Width: 2"
Length: 65'
Color: Black
Bond: Permanent
Type: Linerless Self-Adhering Flashing Tape

The 2" width is an excellent choice for standard deck joists and other narrow framing members where full-width protection is needed without excessive material extending beyond the framing.

3" x 65' G-Tape 3035BK

Part Number: 3035BK-GT-3-65
Width: 3"
Length: 65'
Color: Black
Bond: Permanent
Type: Linerless Self-Adhering Flashing Tape

The 3" width provides additional coverage for wider joists, framing members, beams, and applications where more tape is needed to wrap or protect the sides of the substrate.

4" x 65' G-Tape 3035BK

Part Number: 3035BK-GT-4-65
Width: 4"
Length: 65'
Color: Black
Bond: Permanent
Type: Linerless Self-Adhering Flashing Tape

The 4" width is ideal for larger deck beams, ledger areas, wide framing members, window flashing, wall systems, and exterior construction applications where additional waterproof coverage is required.

G-Tape 3035BK Technical Specifications

Why Use Joist Tape on a Deck?

Water naturally passes through the gaps between deck boards. The decking itself may dry quickly in the sun and moving air, but the top surfaces of the joists underneath can remain damp for much longer.

Fasteners also create areas where water can collect around the deck framing. Over years of weather exposure, repeated wetting and drying can contribute to deterioration of the wood structure underneath the finished deck.

Installing waterproof joist flashing tape before the deck boards go down provides an additional barrier between moisture and the framing.

It is a relatively small part of the total deck project, but once the decking is installed, adding joist protection later becomes extremely difficult. Installing it during initial construction is the logical time to protect the framing.

Great for Pressure-Treated Deck Framing

Pressure-treated lumber is commonly used for outdoor deck construction because it offers improved resistance to moisture, insects, and decay. That does not mean the framing should be left completely unprotected from repeated water exposure.

G-Tape 3035BK adds another waterproof layer over the areas of the framing that receive the greatest direct exposure to rain and drainage from the deck surface.

For builders looking to extend the service life of a deck structure, protecting the joists and beams before decking installation is a simple additional step that can help keep moisture away from vulnerable framing surfaces.

G-Tape 3035BK for Composite & PVC Deck Installations

Premium composite and PVC decking can remain attractive for decades, which makes protecting the wood structure underneath especially important.

It makes little sense to install long-life decking over framing without considering the repeated moisture exposure the joists and beams will experience throughout the life of the deck.

G-Tape 3035BK deck joist flashing tape can be installed before composite, PVC, or traditional wood decking to provide a waterproof protective layer across the underlying framing.

How to Install G-Tape 3035BK Deck Joist Tape

For best results, make sure the framing surface is clean and dry before installation. Remove sawdust, dirt, standing water, oil, and other contaminants that can interfere with adhesion.

Center the tape over the top of the joist or framing member, unroll it along the length of the board, and press it firmly into place. Smooth the tape against the substrate to create consistent contact with the adhesive.

Tear the tape straight by hand when you reach the end of the framing member. No release liner needs to be removed and no cutting tool is normally required.

On wider beams, ledger areas, or framing details, select the 3" or 4" width where additional coverage is needed.

Important Installation Notes

• Apply only to clean, dry surfaces.
• Press the tape firmly against the substrate for maximum adhesion.
• Test compatibility when using on an unfamiliar surface.
• Choose the correct tape width for the framing member and desired coverage.
• Do not use G-Tape as electrical insulation tape.

Why Contractors Choose Linerless G-Tape 3035BK

Deck joist tape is frequently installed across hundreds of linear feet of framing on a single project. Installation speed matters.

G-Tape eliminates the release liner, tears straight by hand, weighs substantially less than many conventional flashing products, and provides permanent waterproof adhesion.

That combination makes it particularly attractive to professional contractors who need to protect the framing without adding unnecessary labor to every joist.

Use the 2" roll for common joist applications, the 3" roll when additional side coverage is useful, and the 4" roll for beams, ledger areas, window flashing, and larger exterior framing details.

BladeRunner's Take on G-Tape 3035BK

The finished deck may be what the homeowner sees, but the framing underneath is what keeps the entire structure standing.

Once premium decking is installed, replacing damaged joists or beams becomes a major project. G-Tape 3035BK gives builders an easy way to add waterproof protection to those framing members while everything is still open and accessible.

The linerless design, hand-tear installation, strong permanent adhesive, waterproof construction, and excellent outdoor weather resistance make 3035BK one of the easiest deck joist flashing tapes to work with.

If you are building a deck that is supposed to last, protect the joists and beams before you cover them.