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 synthetic 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
  • Materials warranty for a period of 10 years
  • Pliable—guaranteed not to crack, harden or shrink due to temperature
  • Sound dampening, reducing board squeaks
  • Apply to horizontal and vertical surfaces including all joists, beams, stair stringers, ledger board and other surfaces
  • Stock available in 2 widths: 1-5/8” (4.13cm) Joist Tape for joists and 3-1/4” (8.26cm) Beam Tape on all double joists and beams

PDF Icon SPAX Deck Tape Technical Data Sheet (300 KB)

Decking Project Calculator

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

Deck Area
(sq ft)
SPAX Joist Tape
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SPAX Beam Tape
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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