Adhesives & Sealants
Flashing
DeckWise
$12-$40/10-ft piece

Deck Flashing for Waterproof Ledger Board Connections

Deck flashing is a critical waterproofing component at the junction between deck ledger board and house structure. Available in metal and self-adhesive membrane styles it prevents water infiltrating behind the ledger where it causes structural rot mold and costly damage. Building codes require proper deck flashing in virtually all jurisdictions.

Key Features

  • Prevents water intrusion at ledger
  • Code-required installation
  • Metal and membrane options
  • Z-bar and through-wall styles
  • Corrosion resistant
  • Critical structural protection

Specifications

Materials: aluminum galvanized steel or membrane | Sizes: 2x4 2x6 2x8 2x10 | Profile: Z-bar L-angle or through-wall | Code: IRC Section R507.2.1

Best For

Ledger board-to-house connections beam-to-post caps rim joist protection and any deck-to-house interface preventing water intrusion.

Compatible Materials

Pressure-treated lumber
House siding
OSB sheathing
House wrap
Masonry
Stucco

Pros & Cons

Pros

  • ✓ Prevents catastrophic water damage
  • ✓ Required by building code
  • ✓ Long-lasting metal
  • ✓ Easy installation
  • ✓ Affordable structural protection

Cons

  • ✗ Must be installed during construction
  • ✗ Requires siding removal for retrofit
  • ✗ Multiple pieces for long runs
  • ✗ Improper installation negates protection
  • ✗ Metal reacts with treated lumber

Installation Tips

Install upper leg behind siding and house wrap with lower leg over ledger top. Overlap splices 3 in with sealant. Do not nail through horizontal face. Use stainless fasteners with pressure-treated lumber. Ensure water directs away from house.

Frequently Asked Questions