Deck Joist and Beam Flashing Tape


Maximize your deck’s life expectancy with SPAX® Deck Joist and Beam Tape.

A typical deck warranty will last 25 or more years—but without a protected deck substructure, splitting and rotting can occur at around 8 to 10 years, according to research by SPAX® Deck Joist and Beam Tape optimizes the life of the deck and ensures a long-lasting, professional installation by protecting fasteners from water damage.

The flexible, waterproof tape is specially engineered with advanced rubber Butyl adhesive to seal off fasteners, joists and beams from moisture. This high-strength, durable barrier prevents premature wood rot while allowing joists to breathe, so that your foundation lasts as long as the deck. And with a UV-resistant engineered film facer, it’s the only deck tape with UV resistance up to 10 years.

SPAX® Deck Joist and Beam Tape is part of our line of complete decking solutions, making professional, high-quality installation easy.

  • Compatible with most deck materials, including pressure treated wood and composite products
  • Protects deck substructure from rot and decay
  • Helps deck screws hold longer and stronger
  • Seals fasteners, preventing moisture penetration
  • Eliminates splitting between freeze and thaw
  • Provides a barrier between wood and galvanized metal
  • Black to hide joists and drillable for ease of use
  • Moisture-resistant, slip and tear resistant
  • The only deck tape that’s UV-resistant up to 10 years
  • Pliable—guaranteed not to crack, harden or shrink due to temperature
  • Sound dampening, reducing board squeaks
  • Stock available in 2 sizes: 1-5/8” for deck joists and 3-1/4” for beams

Joist Tape Calculator

Enter the information below to determine how many rolls are needed for your project.

Deck Area
(sq ft)
SPAX Joist Tape
Rolls of Joist Tape Needed: ?
SPAX Beam Tape
Rolls of Beam Tape Needed: ?

Product Selection

SPAX® Joist Tape

SPAX® Joist Tape

Tape width: 1-5/8"
Part number: 5100007193071

SPAX® Beam Tape

SPAX® Beam Tape

Tape width: 3-1/4"
Part number: 5100007193081