Ventia Platinum Plus Heavy Duty Roof & Wall Underlay is a commercial-grade, heavy-duty synthetic building membrane imported and supplied throughout New Zealand exclusively by EBuilt Ltd (EProducts NZ Ltd).

Engineered and manufactured in Bielsko-Biała, Poland, by mdm NT—one of Europe’s leading producers of technical building wraps—Ventia Platinum Plus represents top-tier building envelope protection. Manufactured under a zero-waste philosophy that recycles post-production materials to eliminate factory atmospheric emissions, Ventia Platinum Plus exceeds New Zealand Building Code requirements. It delivers exceptional strength, vapour permeability, air barrier performance, and weather tightness for high-spec residential, commercial, and light steel or timber-framed constructions.

Advanced Technical Quality & Material Construction

Ventia Platinum Plus is constructed as an ultra-durable, heavy-duty 3-layer microporous membrane:

• Micro-Porous Core Layer: An advanced functional film that acts as a primary water-resistive barrier while providing maximum vapour diffusion to allow internal structural moisture to escape freely.

• Heavy-Duty Protective Layers: High-strength, non-woven spun-bonded polyolefin fabrics laminated to both sides (coloured white on both faces), shielding the functional core against tough job-site handling, foot traffic, and mechanical abrasion.

• Heavyweight Physical Profile: Features a heavyweight mass of 225 g/m² (+/- 10 g/m²) and a thickness of 0.9 mm (+/- 0.15 mm). It delivers extraordinary mechanical strength with maximum tensile force (400 N/50mm machine direction / 260 N/50mm cross direction) and nail-shank tear resistance (250 N machine direction / 320 N cross direction) to prevent tear-outs in extreme wind conditions.

Core Performance Benefits

• Exceptional Vapour Permeability & Moisture Management: Engineered with an ultra-low Sd value of 0.020 m and a vapour resistance well under the 7 MN s/g limit. It allows interior moisture-laden air to diffuse rapidly into the cavity (Lyssy vapour transmission rate up to 2800 g/m² x 24h at 38°C/90%RH), preventing interstitial condensation, timber rot, and mould growth.

• Class W1 Water Resistance & Superior Absorbency: Provides Class W1 liquid water penetration resistance (>= 100 mm head of water) combined with high surface absorbency (> 150 g/m²), holding temporary moisture safely until ambient air movement dries the cavity.

• Dual Air Barrier Capability: Fully tested and qualified for use as an air barrier (air permeance max 0.05 m³/(m² x h x 50 Pa)), limiting wind washing in roof and wall cavities and improving energy efficiency in high-performance builds, including attic spaces and gable ends.

• All Wind Zones & Self-Supporting Roof Spans: Appraised as a self-supporting roof underlay for roof pitches from 3° and above, spanning up to 1,200 mm unsupported. Approved for NZS 3604 and NASH wind zones up to Extra High for roofing and wall overlays, and Very High for stand-alone flexible wall wraps.

• Extended Wall UV Exposure & Toughness: Delivers outstanding job-site durability with up to 180 days UV exposure when installed as a wall underlay (7 days for roof applications), giving builders extended flexibility before exterior claddings are fixed.

• Fire Retardant Safety: Flammability Index of <= 5 tested to AS 1530.2, satisfying NZBC Acceptable Solution C/AS2 requirements for suspended flexible fabrics exposed to view in occupied spaces.

• Versatile Framing & Cladding Integration: Suitable for both timber-framed and NASH light steel-framed buildings. Compatible with masonry tiles, metal tiles, profiled metal roofing, direct-fixed weatherboards, drained cavity wall systems, and masonry veneers.