Tarpi kuorma -autokansiin
When a municipal sports department in a northern Chinese city needed an indoor tennis facility, it had three options: a rigid steel frame building, a tensioned fabric structure, or an air supported structure. The air dome won because it could cover 3,200 square meters without columns and be delivered in under six weeks. The team's biggest concern was fabric selection. That concern is justified: the membrane is the entire structural system. Once you choose the right PVC coated polyester fabric, you have answered most of the questions that determine how long the structure will perform and what it will cost to run.
How Air Supported Structures Work
An air supported structure relies on a pressurized air cushion to hold the fabric envelope in tension. There is no metal frame. The roof and walls are a single sealed membrane that keeps its shape because the internal air pressure pushes outward against the atmosphere. Most air supported structures operate at 250 to 500 Pascals above ambient pressure, which is roughly 0.2 to 0.6 percent of normal atmospheric pressure. That small difference is enough to support loads from snow, wind, and equipment suspended from the ceiling.
Pressure and Stability
Pressure management is the most important daily task. If the pressure drops, the membrane starts to flutter. A few hours of fluttering can cause micro-cracks along the weld lines, which slowly grow into leaks. Good operators install a backup blower and a pressure alarm to protect the structure.
Shape and Load Distribution
The shape of an air supported structure also affects the fabric load. An arched or domed profile distributes tension smoothly, while flat panels create stress concentrations at the seams. Curved surfaces help snow slide off, reducing the dead load on the membrane. In regions with heavy snowfall, engineers often increase the internal pressure to stiffen the roof, but this also places more tension on the fabric. That is why the fabric specification must be matched to the planned operating pressure, not just the structural span.
Choosing the Membrane Fabric for an Air Dome
Fabric selection starts with the coating system. PVC coated polyester fabric is the standard because it combines strength, flexibility, and affordability. The polyester base layer carries the tensile load, while the PVC coating handles weather, UV, and wear. For air supported structures with a longer service life, a PVDF top coat is a common upgrade. PVDF helps the membrane resist surface dirt, reduces the rate of plasticizer migration, and makes cleaning easier.
Two product categories dominate the specifications for air domes. The 1100 g/m² PVDF tensile membrane is a versatile choice for medium-span structures, sports halls, and temporary warehouses. A project covering 2,000 to 4,000 square meters, with a span of 25 to 35 meters, often arrives at this specification after a load calculation. The membrane's tensile strength and tear resistance are adequate for moderate wind and snow zones, and the weight keeps the cost reasonable.
1100g PVDF Tensile Membrane Fabric for Medium-Span Air Domes This 1100g PVDF membrane offers a balance of strength and cost, suitable for medium-span structures like sports halls and warehouses. With a tensile strength of 5500-6000N and self-cleaning properties, it maintains appearance and durability in moderate climates. View Product → For larger structures or harsher environments, the 1250 g/m² PVDF architecture membrane is the heavier option. It offers a higher breaking strength and better dimensional stability under continuous tension. Large air dome sports facilities, logistic hubs, and industrial work platforms in northern climates tend to choose this material. The additional weight also improves the structure's stiffness, which means the air pressure does not have to be pushed as high for the same snow load.
1250g PVDF Architecture Membrane for Large-Span and Harsh Environments Heavier 1250g PVDF membrane provides higher breaking strength and dimensional stability, ideal for large air domes in harsh conditions. Its titanium dioxide coating resists yellowing, and high tensile strength above 7000N ensures reliability under tension. View Product → The table below compares the three most common membrane specifications used in air supported structures.
| Fabric | Typical application | Key considerations |
|---|---|---|
| 950g PVDF plus acrylic | Smaller enclosures, event tents, seasonal structures | Lighter weight, lower upfront cost, suitable for moderate wind zones |
| 1100g PVDF tensile membrane | Medium-span air domes, sports halls | Balanced strength and cost, reliable performance in most climates |
| 1250g PVDF architecture membrane | Large-span structures, heavy snow or wind regions | Highest durability, excellent tear resistance, long service life |
Besides the fabric weight, buyers should also look at the welding specification. Air supported structures are assembled by joining panels with high-frequency or hot-air welding. The weld strength should ideally be at least 80 percent of the base fabric's breaking strength. When welding parameters are not carefully controlled, the weld line becomes the weakest point in the structure. A fabric with excellent tensile strength and poor welding will still fail early at the seams.
How to Read a Fabric Specification
When you review a membrane datasheet, start with the breaking strength in both warp and weft directions. The tensile strength in the warp direction is usually higher because the fabric is more compact along the weave. The tear strength is equally important for an air supported structure because a puncture can propagate into a long tear under pressure. A tear strength of 500 Newtons or greater is common for membrane fabrics in this application.
Where Air Supported Structures Are Used
The application range has expanded beyond portable tents. Air supported structures now house permanent sports facilities, indoor swimming pools, tennis courts, and artificial turf fields. In these settings, the membrane must maintain light transmission for daytime use, resist UV radiation, and allow installation of ventilation or heating equipment.
Industrial operators use air domes to create temporary warehouses, construction enclosures, and work shelters. A manufacturing plant that needs covered space for a new production line might install an air dome while a permanent hall is under construction. Mining and oilfield sites use air supported structures as maintenance bays and equipment shelters because they can be moved when operations shift.
Event and exhibition organizers also benefit from the large clear span. An air dome of 40 meters wide has no interior columns, which creates flexible floor plans for exhibitions, markets, and indoor sports competitions. The structure can be inflated in days, used for a season, and then deflated or relocated.
To see real project examples, you can review these popular air film buildings that showcase different typologies and uses.
Key Purchase and Management Decisions
Procurement of an air supported structure involves more than comparing fabric prices. You need to define the location's wind and snow loads, the operating pressure, and the expected service life. From those inputs, the fabric specification can be calculated.
What to Specify in Your Tender
Write down the minimum fabric weight, the required tensile strength, and the coating type. Use the site-specific wind pressure from the national building code. Include sea freight and import duties if you are sourcing from overseas. Most importantly, ask the fabric manufacturer for a welding guarantee and a repair kit. At minimum, gather these three numbers before you call a supplier:
- Maximum wind speed for the site location, taken from the local building code
- Design snow load per square meter, including the safety factor used by the structural engineer
- Planned internal operating pressure in Pascals, plus the backup blower specification
Operating Costs and Maintenance
An air supported structure runs on electricity. The blowers operate continually, and in winter, heating and dehumidification can account for a large share of the running costs. A backup power supply is mandatory because a sudden deflation in a storm can damage the structure. In cold climates, the internal heating system also keeps the membrane flexible and prevents ice from forming on the inside surface.
Routine inspection of the membrane helps identify the first signs of surface crazing or plasticizer migration. Prompt attention to small punctures prevents them from expanding into large tears. Cleaning the membrane with a mild detergent and soft brush preserves the coating and extends its lifespan. Taking the time to review these maintenance steps for inflatable tents will also help with larger air supported structures.
Conclusion: Make the Specification Decision Early
An air supported structure is only as good as its membrane. The 1100g and 1250g PVDF fabrics cover most medium and large projects, but the final choice must match the site conditions and the budget. When you set the specification early and work with a manufacturer that can supply test data and welding consistency, the structure will deliver decades of reliable shelter. Ask for sample swatches, test certificates, and weld samples before ordering. That small step prevents the most expensive mistake an air dome project can make: choosing a lightweight fabric that fails after a few winters.
