At first glance it appears pretty straight forward: metal roofs are more expensive, fabric roofs are cheaper.
However when all factors are considered, costs are often very similar. This is due in part to the increasing costs of high-tech membranes and complexity and one off mature of components used in tensile fabric structures. At the same time metal roofing products are reducing in price and metal roofs are more durable.
So if costs are on par, what are the differences between a metal roof and fabric roof, particularly if the roof is part of an open shade structure?
The Spantech design eliminates roosting sites for birds and other vermin. This is primarily because the Spantech panel is self supporting. Spantech can span up to 40 metres without any internal trusses. Spantech also design the supports and connections to eliminate all potential roosting spots.
Eliminating birds and vermin results in more hygienic facilities and there is less cleaning and ongoing maintenance necessary. It is an important factor in the design of any open structure particularly if utilised by children or the public.
Many fabric products are designed to be porous to reduce the wind loads on their weaker frames or fixings. Spantech roofs are completely waterproof.
Shade sails are typically guaranteed for 10 years. Spantech Shade Structures can be provided with a manufacturer warranty of up to 36 years (subject to conditions).
Shade cloth and many low-tech fabrics stretch when cleaned. New high-tech membranes are finished so that they need cleaning less often. However, how do you access a fabric structure to carry out cleaning?
Spantech roofs are fitted with a roof access system so the roof can be regularly inspected and cleaned to ensure its longevity.
Spantech’s curved roof is formed with Spantech panels rolled from long-lasting Colorbond steel, a stronger more permanent alternative to even the strongest shade cloth or membrane roof.
Each Spantech Shade Structure is fully engineered to suit the location and soil conditions and is certified by a Structural Engineer. The Building Code of Australia generally places permanent structures in a different class to shade cloth structures. The result is that cloth covered structures are lighter than and not as strong as permanent shade facilities.
Metal roofs are not flammable. Only the most expensive fabrics are fire resistant.
Spantech buildings, including Spantech Shade Structures, can be cyclone rated. Shade sails are rarely cyclone rated.
Typical shade cloths and membranes are not designed to resist hail. Spantech roofing panels are up to 1.2mm thick, more than twice the thickness of typical Colorbond roofing making it very highly resistant to hail and storm damage.
Membranes can form almost any shape, however, the supporting structure required to achieve the shape is often complex and expensive. Spantech panels can also achieve complex shapes. Spantech curved panels are a segment of a circle of almost any radius and the flat panel can be sprung curved or slightly twisted for effect. The main advantage of the Spantech roof is that it requires little or no internal support to achieve the required shape.
Many shade cloths and membranes do not block all harmful UV light creating a false sense of security and protection. The fabric also breaks down with prolonged UV exposure. The paint system used on steel may fade over time, however, UV will not affect the strength or life of the steel and steel completely blocks all UV light.
Heat and Noise
Fabric roofs rely on the efficiency of the material to deflect heat and noise. Many fabrics have no affect on either. Spantech roofs can be fitted with a ceiling and any level of insulation to achieve the required amount of thermal and acoustic regulation.
A number of new high-tech membranes affect lighting conditions in unusual ways. Operators report that despite membranes being translucent it is still necessary to run lights during the day to counteract glare or to boost the overall lighting level. At night light is lost through the membrane resulting in less effective interior lighting. Either scenario adds to ongoing operating costs.
Spantech buildings can be designed to be fully enclosed if required. This means that a simple shade structure over a basketball court can become a fully functional indoor sports centre. It affords owners with options and protects the initial capital investment in the shade structure.
Many companies claim that their product is cost effective. However, few consider the full life cycle of a structure including the ongoing operating costs and maintenance. Spantech is confident that over the life of the building, a Spantech Shade Structure is more cost effective than a comparable fabric covered structure.
The initial capital cost of many high-tech fabric roofs is often more expensive than a Spantech metal roof, particularly when large areas are required to be covered.