Ventia Black Self-Adhesive Underlay 1.5m x 50m | NZ
Ventia Roof Underlay is a premium metal roof and wall underlay with an integrated drainage mat, providing superior moisture protection and breathability. Size: 1.5m x 25m (37.5m²). Ideal for residential and commercial roofing projects across New Zealand.
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Product Details
Ventia Iron Black Self-Adhesive Underlay — 1.5m x 50m (75m²)
Premium Weather Protection Built for New Zealand Conditions
Ventia Self-Adhesive Underlay is a premium self-adhesive membrane designed for metal roof and wall protection, offering superior waterproofing and easy installation. This high-performance membrane delivers fully adhered weather protection for RAB (Rigid Air Barrier) wall systems, all while maintaining exceptional breathability — a crucial balance that keeps moisture out without trapping it inside the building envelope.
Unlike traditional wraps that rely purely on mechanical fixing, Ventia Iron Black's self-adhesive design creates a continuous, fully bonded barrier against wind and water. This means fewer gaps, fewer failure points, and a tighter building envelope from day one.
Certified for New Zealand Building Standards
Confidence in a product starts with proper certification, and Ventia Iron Black delivers on that front. It holds BRANZ Appraisal No. 1258 and has been independently assessed to exceed the requirements set out in the New Zealand Building Code (NZBC). For builders, specifiers, and homeowners alike, this certification provides peace of mind that the product has been rigorously tested for New Zealand's demanding climate and building conditions.
Versatile Applications Across Your Build
Ventia Iron Black has been engineered to perform across a wide range of construction scenarios, making it a genuinely flexible choice for both roofing and wall applications:
Roof and Wall Underlay for SIP Construction
The membrane is well suited to Structural Insulated Panel (SIP) builds, providing reliable weather protection across both roof and wall elements of these increasingly popular construction systems.
Cross Laminated Timber (CLT) Construction
For projects using CLT alongside branded cladding systems such as James Hardie, GIB Weatherline, or Ecoply, Ventia Iron Black integrates smoothly into the overall weathertightness strategy.
Wall Underlay Over Rigid Substrates
It can be adhered directly to rigid underlays including plywood, OSB boarding, and fibre cement, whether fixed to timber or steel-framed walls. This makes it an adaptable option regardless of your framing material.
Roof Underlay on Pitched Roofs
As a roof underlay, it's suitable for pitches from a minimum of 3° up to just under 8°, adhered to plywood or OSB boarding — ideal for lower-pitch roof designs that require dependable, fully bonded protection.
Temporary Weathertightness Protection
During the build process, Ventia Iron Black can also serve as a temporary weather barrier, protecting internal works and allowing trades to progress before final wall cladding is installed. This flexibility helps keep projects moving even when weather or scheduling delays cladding installation.
Substrate Thickness Requirements
To ensure proper performance and compliance, minimum substrate thicknesses apply:
- Plywood for walls: minimum 7mm thick
- Plywood for roofs: minimum 15mm thick
- Fibre cement: minimum 6mm thick
Meeting these specifications ensures the underlay bonds correctly and performs as intended across the life of the building.
Built for Every Wind Zone
New Zealand's varied climate means buildings need to withstand everything from coastal gusts to exposed high-country winds. Ventia Iron Black is rated as suitable for all wind zones, giving builders confidence that the product will perform reliably regardless of region or site exposure.
Completing the System
For a fully compliant and effective weathertightness system, Ventia Iron Black should be used alongside ViBest Super Pro Flashing Tape, Seals, and Corner Moulds. These complementary products ensure that laps, penetrations, and corners are properly sealed, eliminating weak points and extending the overall performance of the weather barrier.
Order Ventia Iron Black Today
Whether you're working on a residential build, a commercial project, or specifying materials for an upcoming job, Ventia Iron Black offers the certified performance and flexibility New Zealand builders rely on.
Feel free to place your order by emailing us at [email protected] or call us at 0221 969 021 — we'd love to hear from you!
