Ventia Iron Roof & Wall Underlay 1.37m x 36.5m (50m²) | NZ

Ventia Iron – Roof & Wall Underlay 1.37m x 36.5m (50m²)

The Ventia Iron underlay is a premium roof and wall underlay offering exceptional breathability and durability, purpose-built for New Zealand's residential building projects. This 1.37m width variant is ideal for standard residential re-roofs, new home builds, and smaller-scale projects where a manageable, easy-to-handle roll size is preferred over larger commercial formats.

Engineered for Breathability and Long-Term Protection

Ventia Iron is designed to withstand up to 90 days of UV exposure, giving builders a practical window to complete installation without compromising the underlay's protective performance. Based on independent laboratory testing, this underlay delivers 10 times more breathability than competing products — a critical feature for effective moisture management within the roof and wall cavity. This superior breathability helps prevent condensation build-up, reducing the long-term risk of mould, timber rot, and structural corrosion, and contributing to a healthier, longer-lasting building envelope.

Alongside its breathability, Ventia Iron features high tear resistance, ensuring the material holds up well during handling, fixing, and exposure to on-site conditions before the roof or wall cladding is completed. This reduces the likelihood of damage during installation, minimising wastage and the need for repairs or replacement sections.

Reliable Performance Across All Wind Zones

Ventia Iron is suitable for use in all New Zealand wind zones, and delivers extra high wind zone performance when installed as an overlay for rigid wall underlays — making it a dependable choice regardless of your project's location or exposure level. Its fire-retardant properties provide an added layer of safety, supporting compliance with New Zealand building performance requirements and giving builders and homeowners confidence in the product's overall reliability.

The Right Fit for Your Project

Unlike the wider 2.74m roll designed for large-scale commercial applications, this 1.37m x 36.5m (50m²) roll offers a more manageable format that's easier to transport, store, and manoeuvre on standard residential job sites — particularly useful for smaller crews or single-storey homes where a lighter, more compact roll simplifies handling without sacrificing performance.

Ventia Iron is available in three roll widths — 1.37m, 1.5m, and 2.74m — allowing builders to select the most appropriate size for the scale and layout of their specific project. Whether you're working on a compact residential renovation or matching an existing product specification across multiple builds, this range of widths ensures there's a suitable option for every job.

Versatile Roof and Wall Application

Beyond its role as a roof underlay, Ventia Iron performs equally well in wall applications, giving builders the flexibility to standardise their underlay choice across an entire project. This consistency simplifies ordering, reduces the need to source multiple products, and ensures uniform weather protection throughout the building envelope.

Product Specifications

• Roll Size: 1.37m x 36.5m (50m² per roll)
• Weight: 4.90 kg
• UV resistance: up to 90 days
• Breathability: 10x greater than competitors (independently lab tested)
• High tear resistance
• Suitable for all wind zones (extra high performance as overlay for rigid wall underlays)
• Fire retardant
• Suitable for roof and wall underlay applications
• Available in 1.37m, 1.5m, and 2.74m roll widths

Why Choose Ventia Iron?

For residential builders and homeowners across New Zealand looking for a reliable, high-breathability underlay in a more manageable roll size, Ventia Iron 1.37m offers the same trusted performance as the wider commercial format — with the convenience of easier handling for smaller-scale projects.

Order Today

Ready to secure your Ventia Iron Roof & Wall Underlay 1.37m x 36.5m? Feel free to place your order by emailing us at [email protected] or calling us at 0221969021 — our team would love to hear from you and help you get the right materials for your next project.