Joist Tape for Decking 1-5/8in x 50ft, 6 Rolls - Waterproof Butyl

In this review of the Joist Tape for Decking, the bottom line is simple: this 6-roll pack is best for homeowners, builders, and contractors who need a cost-effective way to add long-lasting waterproof protection to deck joists and exposed beams. The single biggest reason to buy is the combination of coverage and weather resistance - six rolls at 1-5/8in x 50ft provide 300 ft of self-adhesive butyl flashing that can be cut to length and applied to wood, metal or plastic to reduce water damage and extend structure life.

Key Features

• 6 Rolls, 300 ft total: The package includes six 1-5/8in x 50ft rolls so you get ample coverage and can customize lengths for multiple joists or beams.
• Waterproof butyl adhesive: The butyl formulation provides a continuous, impermeable seal that helps prevent water intrusion and rot on exposed wood joists.
• Self-adhesive application: The tape sticks instantly to clean, dry wood and metal surfaces, bonding to irregular profiles for a seamless flashing layer.
• Wide temperature tolerance: Rated to withstand temperatures from -20F to 230F, it remains flexible and adherent across seasonal extremes.
• Versatile compatibility: Suitable for wood, metal, plastic and rubber surfaces, making it a practical choice for decks, roofs and sheds.

Who It's For

This product suits homeowners renovating a deck, contractors doing routine joist flashing, and DIY builders who want an easy-to-install, long-run solution. The package size and format are particularly useful when multiple joists or a larger deck area needs protection without repeated trips to buy more tape.

Those who need a thin trim-level seal or decorative finish should look elsewhere, as this is a functional flashing product focused on protection rather than appearance. Also, users who expect instant bubble-free perfection may need to allow time and care when removing the backing to get the best adhesion.

Pros & Cons

Pros

• Good value per linear foot thanks to six rolls providing 300 ft of tape.
• Strong waterproofing and anti-damage performance from the butyl adhesive.
• Performs well in a wide temperature range, maintaining flexibility in heat and cold.
• Adheres to a variety of materials, reducing the need for multiple specialized products.

Cons

• Some users report the plastic backing can be tricky to remove cleanly, which can complicate application.
• Adhesion experiences are mixed; surface preparation and care during installation affect results.

Specifications

Brand	MOLYLY
Roll size	1-5/8in x 50ft
Quantity	6 rolls (300 ft total)
Material	Butyl adhesive
Temperature range	-20F to 230F
Applications	Joists, decks, roofs, sheds; wood, metal, plastic, rubber

Our Verdict

The Joist Tape for Decking is a practical, budget-friendly choice for anyone who needs reliable flashing material in quantity. With 300 ft of self-adhesive butyl tape and broad temperature tolerance, it protects joists and beams effectively; just allow care when removing the backing and prepare surfaces for best adhesion. Overall it offers strong value and durability for routine deck and roof protection.

Frequently Asked Questions

Can this tape be used on metal and plastic?
Yes. The product bonds to wood, metal, plastic and rubber surfaces when applied to clean, dry material.

What temperatures will the tape tolerate?
The tape is rated to withstand from -20F up to 230F while retaining flexibility and adhesion.

How much coverage do I get with the package?
The six rolls provide a total of 300 ft of tape, each roll measuring 1-5/8in x 50ft and easily cut to the lengths you need.