Roof inflatable structure OKCAS®

for industrial applicationswith polyester membranewith PVC membrane

Overview
OKCAS® (Okatent Cushion Air System) is a pressurized double-layer roofing system for modular and industrial buildings. It creates an air chamber between two PVC-coated polyester membrane layers to improve thermal and acoustic performance, increase structural tension and deliver a uniform visual finish.

How it works
The system maintains a controlled air chamber between two membrane layers at a constant pressure of 0.8–1.2 mbar. A low-consumption 105 W turbine with a pressure switch operates in a largely closed circuit and activates intermittently to preserve the chamber pressure and membrane tension, reducing flapping and condensation risk.

Main components of an OKCAS® roof

• Air chamber: Pressurized cushion between membranes; operating pressure 0.8–1.2 mbar; stabilized by a 105 W turbine and pressure switch in a closed circuit.
• Insulating fibre layer: PET wool (non-woven recycled polyester) optional insertion to boost thermal and acoustic performance; system with fibre can reach ~0.28 W/m²·K and ~20 dB acoustic reduction.
• Single membranes: Exterior and interior PVC-coated polyester membranes fixed with Keder; typical membrane mass 650 g/m²; fire classification M2 (NFP 82507) when specified.
• Microperforated inner membrane: Improves acoustic absorption when combined with the air chamber and insulating fibre.

Differences vs standard single-layer canvas roofs

• Material: single PVC-coated polyester membrane vs two PVC-coated polyester membranes with an intermediate pressurized air chamber.
• Operation: conventionally tensioned and fixed with Keder and HF welding vs system maintained by a 105 W turbine and pressostat in a closed circuit.
• Typical use: small-format or temporary structures vs large-scale applications (padel/tennis stadiums, hangars, industrial facilities, megafactories).

Available configurations / Insulation options

• B – OKCAS® simple insulation: U-value ≈ 2.1 W/m²·K. Double membrane with pressurized air chamber reduces thermal transmittance and condensation risk.
• A – OKCAS® advanced insulation: U-value ≈ 0.8 W/m²·K. Adds insulating material (e.g. PET wool) inside the chamber for higher thermal performance.
• A+ – OKCAS® with insulation + extreme ventilation: U-value ≈ 0.5 W/m²·K. Combination of opaque outer layer, pressurized air chamber and translucent inner layer with insulation for thermal control and diffused natural light.

Benefits

• Thermal insulation: Reduced heat transfer and improved indoor comfort; better performance under snow loads.
• Condensation control: Air cushion decouples inner and outer surfaces, lowering condensation risk.
• Acoustic insulation: Air chamber plus insulating fibre improves sound absorption.
• Watertightness: Double-layer solution with HF welded Keder and airtight chamber enhances waterproofing.
• Movement reduction: Constant pressurization prevents membrane flapping in strong winds.
• Durability: Two tensioned PVC textile layers increase abrasion and wear resistance.
• Better drainage: Air cushioning helps avoid water or snow stagnation and improves runoff.
• Anti-corrosion: Textile membranes avoid through-fixings and do not corrode.
• Modular assembly: Faster installation, dismountable design suitable for relocatable modular buildings.
• Aesthetics: Uniform visual result with identical air cushions manufactured in single pieces.

Success stories / Typical projects

• OKCAS® Fiver (Switzerland): project incorporating synthetic fibres for high thermal and acoustic requirements; >10 cm roof insulation in that installation.
• R Padel Indoor Club (Spain): custom sports roof covering multiple padel courts with large spans and sandwich panel side enclosures.
• Volkswagen (industrial application): OKCAS® roofs used in modular industrial buildings to expand production areas.

Patents and track record
OKCAS® was patented in 2023 and has been installed on multiple projects demonstrating suitability for sports facilities, hangars, warehouses and large-span industrial buildings.

Technical specifications

• Denomination: OKCAS® (Okatent Cushion Air System)
• Operating internal pressure: 0.8–1.2 mbar
• Turbine: low-consumption 105 W turbine with pressure switch (closed circuit)
• Membrane material: PVC-coated polyester textile membrane
• Membrane mass: 650 g/m²
• Fire protection: M2 fire-retardant according to NFP 82507 (when specified)
• Insulating fibre: PET wool (recycled polyester, non-woven)
• Thermal insulation (system with fibre): approx. 0.28 W/m²·K
• Acoustic reduction (with insulating layer): approx. 20 dB
• U-values by variant: B ≈ 2.1 W/m²·K; A ≈ 0.8 W/m²·K; A+ ≈ 0.5 W/m²·K
• Typical uses: padel and tennis stadiums, sports covers, hangars, megafactories, industrial facilities
• System type: pressurized double-layer membrane roof (modular, demountable)
• Patent: granted in 2023; multiple installations executed