Description

Getting building basics right is critical for weathertight construction. In this article, we look at the correct way to install wall underlay and flashing tape to exterior window and door openings in light timber or lightweight steel-framed dwellings before installing aluminium joinery.

There is potential over the life of a dwelling for water to enter through the exterior cladding into the wall assembly. This can occur through the junctions between the exterior joinery and the cladding or through the seals and joints of aluminium joinery, particularly at corners.

This ingress moisture may reach the wall framing, and as the framing is vulnerable, it needs protection.

Scope

This article includes:

• Protecting framing from moisture
  • Flexible flashing tape
• Construction sequence starts the same
  • Step 1: Wall underlay
  • Step 2: Cut and fold wall underlay to opening
• Conformable flashing tape installation (use steps 3–6)
  • Step 3: Install tape to the top corners
  • Step 4: Fold overhanging tape back
  • Step 5: Repeat for sill
  • Step 6: Fold overhanging tape back
• Non-conformable flashing tape installation (use steps 7–11)
  • Step 7: Fix tape diagonally across corners
  • Step 8: Install flashing tape to the top corners
  • Step 9: Cut, fold and fix flashing tape
  • Step 10: Install flashing tape to sill
  • Step 11: Cut, fold and fix tape for sill
• Several key considerations