Ventia Roof Underlay – Metal Roof & Wall Drainage Mat NZ

VENTIA Metal Roof & Wall Underlay with Drainage Mat 1.5m x 25m (37.5m²)

VENTIA Metal Roof & Wall Underlay with Drainage Mat 1.5m x 25m (37.5m²) is a premium, highly breathable roof and wall underlay specifically engineered for modern metal roofing and wall cladding systems. Designed to deliver outstanding moisture management, ventilation, and long-term building protection, this professional-grade underlay features an integrated drainage mat that helps improve the performance and durability of the entire building envelope.

Manufactured for New Zealand building conditions, VENTIA Metal (Ventia Iron 1136) is an ideal solution for residential, commercial, agricultural, and industrial projects where superior breathability and effective drainage are essential. Whether you're constructing a new building or upgrading an existing property, this advanced underlay provides the protection needed to help maintain a dry, energy-efficient, and long-lasting structure.

One of the standout features of VENTIA Metal is its highly breathable membrane, which allows water vapour to escape while preventing unwanted moisture from entering the building. This significantly reduces the risk of condensation, mould growth, timber deterioration, and insulation damage. By allowing trapped moisture to dissipate naturally, the underlay contributes to a healthier indoor environment and improved building performance.

The integrated drainage mat creates a continuous drainage cavity beneath metal roofing, allowing water that penetrates beneath the roofing sheets to safely drain away. At the same time, it promotes airflow beneath the roofing material, helping reduce condensation and supporting ventilation throughout the roof system.

VENTIA Metal has been specifically designed for installation beneath open-pan style metal roofing profiles, including:

• Eurostyle
• TRS Standing Seam
• ESPAN
• Eurotray
• Euroline

These roofing systems require effective drainage and ventilation to maximise their performance and lifespan, making VENTIA Metal an excellent choice for builders, roofing contractors, and architects seeking reliable long-term protection.

The product is also highly recommended for retrofit wall insulation projects in existing homes where the external cladding is not being removed. This makes it an excellent solution for improving the thermal efficiency of older buildings without requiring extensive structural alterations.

Another important advantage is its ability to help minimise oil canning in long-run metal roofing sheets. By providing a cushioned drainage layer beneath the roofing material, the product helps reduce visible waviness and contributes to a cleaner, more professional roof finish.

Key Features

• Highly breathable roof and wall underlay
• Integrated drainage mat for enhanced moisture management
• Allows water vapour to escape while preventing water ingress
• Promotes ventilation beneath metal roofing systems
• Helps reduce condensation and mould growth
• Designed specifically for open-pan metal roofing profiles
• Suitable for retrofit wall insulation applications
• Helps minimise oil canning in long-run metal roofing sheets
• Improves the durability and performance of the building envelope
• Ideal for residential, commercial, industrial, and agricultural buildings
• Lightweight, durable, and easy to install

Technical Specifications

• Product: VENTIA Metal Roof & Wall Underlay with Drainage Mat
• Product Type: Ventia Iron 1136
• Roll Size: 1.5m × 25m (37.5m²)
• Weight: 6.00 kg
• Application: Roofs and walls
• Suitable For: Residential, commercial, industrial, and agricultural construction

Ideal Applications

VENTIA Metal is suitable for a wide range of projects, including:

• Residential homes
• Commercial buildings
• Industrial facilities
• Farm buildings and sheds
• Architectural metal roofing systems
• Standing seam roofing
• Long-run metal roofing
• Wall cladding systems
• Retrofit insulation projects
• New construction and renovation work

By combining advanced breathability with an integrated drainage mat, VENTIA Metal provides comprehensive protection against moisture while supporting the long-term performance of roofing and wall systems. It is an excellent investment for builders and property owners who want reliable protection, improved ventilation, and enhanced building durability.

At One Roofing, we are committed to supplying premium roofing and building products that meet the demands of New Zealand's construction industry. Our knowledgeable team is ready to help you select the right materials for your project and ensure you receive products you can rely on.

Feel free to place your order by emailing us at [email protected] or call us at 022 196 9021 – we'd love to hear from you!