DRYSTUD Class 4 Vapour Permeable Wall Wrap

A wall needs to do two things at once: keep weather out and moisture vapour out. DRYSTUD is a breathable wall wrap built to do both. Fitted over the frame and behind the cladding, it resists water coming in, while the Class 4 vapour permeability lets damp air from inside the wall escape, which cuts the risk of condensation, mould and rot in the framing.

Key benefits

• Breathable: Class 4 vapour permeable, so moisture can escape from the wall
• Water resistant: High water barrier rating to shed water that gets behind the cladding
• Air-tight when the overlaps are properly taped, which reduces air leakage and helps energy efficiency
• Tough: Tri-laminate synthetic non-woven construction that’s light but tough and tear resistant
• Easy to work with: Translucent, so studs, openings and corners are easy to find
• Fire retardant: flammability index of 5 or less (AS/NZS 1530 Part 2)
• Up to 60 days of UV exposure allowed before cladding goes on
• Compliant: Classified to AS/NZS 4200.1 and installed to AS 4200.2

Where to use it

• Timber-framed walls behind fibre cement or timber cladding
• Steel-framed walls
• Double brick and brick veneer drained cavity walls
• New builds, extensions and renovations

Sizes and coverage

• 1350mm wide x 30m long: 40.5 m² per roll
• 1500mm wide x 30m long: 45.0 m² per roll

How many rolls do you need?

Divide your wall area by the roll coverage. Then add extra for overlaps, openings and offcuts.

Allow for overlaps and openings when working out how many rolls you need, and order a little extra.

Technical snapshot

• Duty classification: light wall (AS/NZS 4200.1)
• Vapour classification: Class 4 vapour permeable
• Vapour permeability: 3 ±1 µg/N.s
• Water barrier: high
• Air control: air barrier when taped
• Flammability index: 5 or less
• Allowable UV exposure before cladding: 60 days
• Non-reflective and non-conductive

Installation tips

• Install to AS 4200.2 and the manufacturer’s instructions.
• Run the wrap over the full wall frame, lapping each course so water sheds outwards.
• Tape the overlaps with a compatible joining tape to make the wrap air-tight, and flash around windows and doors with compatible flashing tape.
• Cover with cladding within 60 days, and repair any tears or damage before then.
• Store rolls clean, dry and out of the weather and sun.

Wall wrap or foil vapour barrier

DRYSTUD is a breathable wall wrap, not a vapour barrier. It lets moisture out so walls can dry. If you need a reflective, vapour-blocking layer instead (for example in a steel shed), see our Sancell reflective foil range. The right choice depends on your climate zone and wall design, so check the NCC condensation requirements.

Pair it with wall insulation

Wall wrap goes on the outside of the frame, and insulation goes between the studs. Browse our Earthwool wall batts to complete the wall.

FAQ

What does Class 4 vapour permeable mean? It’s a high vapour permeability class, meaning the wrap lets moisture vapour pass through easily so the wall can dry out.
Is it waterproof? It’s rated as a high water barrier, which stops liquid water getting into the frame, while still letting vapour escape.
How long can it stay exposed before cladding? Up to 60 days of UV exposure.
Can I use it on steel and timber frames? Yes, it suits both.
Is it a roof sarking? No. It’s a light-duty wall wrap. For roofs, see our roof blankets and sarking.
Do I need to tape it? Taping the overlaps is what makes it air-tight, so yes, tape the joins as the instructions say.
Which roll size do I need? Divide your wall area by the roll coverage and add an allowance for overlaps and offcuts.
Can I collect in store? Yes, click-and-collect is available at checkout.