Aztec MetalFlash Square Base No 4 (70–175 mm) – High‑Temp Red Silicone The Aztec MetalFlash Square Base No 4 is a high-performance pipe flashing engineered for rugged heat environments. Its heat-resistant red silicone sleeve provides secure sealing for penetrations between 70 mm and 175 mm, making it ideal for exhaust flues and hot-venting applications on metal roofs. Specifications Feature Details Penetration range 70–175 mm pipe or conduit Temperature rating Up to 260 °C intermittently (silicone) Base type Square aluminium – approximately 280 mm wide Roof pitch compatibility Suitable for flat, corrugated and standing-seam metal roofs up to 45° Colours Red silicone (hi‑temp), plus black or grey EPDM variants Warranty 25‑year guarantee Why Choose the Silicone Version Exceptional heat resistance — the red silicone cone is suitable for PPE systems and flues, rated to 260 °C intermittently Durable flexibility — silicone retains elasticity under UV, ozone and extreme temperatures Adaptable installation — square aluminium base conforms to all roof profiles without needing mastics or heat Complex penetrations made simple — customise the silicone sleeve by cutting to fit the exact pipe size before installation Product Variants Black or grey EPDM versions suitable for standard or cooler piping penetrations up to 135 °C Other sizes: No 3: 5–125 mm No 6: 125–230 mm Available in red silicone or EPDM, plus custom BHP colour matches Typical Applications Ideal for sealing rooftop penetrations such as: Hot-air exhausts and flue vents Solar hot water or thermal panel outlets HVAC systems with medium to high-temperature discharge Exterior conduits and pipework on pitched or commercial metal roofs Installation Overview Trim the red silicone cone to fit snugly around the pipe. Press the base into the metal roof profile until fully seated. Secure with self-drilling screws or sealed rivets. Seal the base’s perimeter using a quality roof-grade silicone sealant. No hot works or special tools needed; installation is efficient, clean, and secure. The Aztec MetalFlash Square Base No 4 (70–175 mm Silicone) offers exceptional thermal performance, durability, and ease of installation. With a high-temperature silicone cone, adaptable aluminium base and 25-year warranty, it’s the ideal solution for sealing hot-air penetrations on modern metal roofs. For different performance needs or colour matching, the EPDM versions and other sizes are also available.
