The Ubbink OFT 4 Flat Roof Vent Terminal is a uninsulated twin-wall capped vent stack, engineered to provide high-capacity ventilation for flat roofs with an integrated condensation drain system. Designed for versatility, the OFT 4 is compatible with a variety of roof coverings including Asphalt, Built-Up Felt, EPDM and Bitumen felts.

This model features a low-resistance cowl (<1.0 Pascal at 225m³/h), making it ideal for systems where minimal airflow resistance is critical. The stack includes a twin-walled pipe above the roofline for enhanced airflow performance and built-in condensation management.

Key Features:

• Large Free Vent Area – Enables excellent airflow and ventilation performance.
• Ultra-Low Pascal Resistance – <1.0Pa at 225m³/h for efficient ventilation.
• Twin-Wall Pipe with Condensation Drain – Helps prevent moisture build-up within the stack.
• High-Quality Polypropylene (PP) – Durable and weather-resistant in all UK conditions.
• No Rain Ingress – Specially designed cowl prevents water entry.
• Modern, Elegant Finish – Clean design blends discreetly into flat roofing systems.
• Suitable for New Build or Renovation – A flexible solution for a wide range of projects.

Five flange types are available to suit each material, ensuring a secure and watertight installation every time.

Compatibility & Flange Options:

• Asphalt
• Built-Up Felt
• EPDM
• Bitumen

Available Diameters: - 10mm & 166mm options.

Note:

* Not recommended for installation in extreme wind zones due to the open-style cowl.