When it comes to erecting flat roofing for commercial or industrial buildings, various factors such as durability, cost and speed of installation must all be taken into account. However, Australia's unforgiving climate also makes heat resistance one of the most important factors to consider when choosing your roofing materials. The materials your roof is constructed of must be able to stand up to the damaging effects of intense heat and UV radiation without crumbling or perishing, while providing sufficient heat insulation to prevent the interior of the building becoming unbearably hot.
As such, commercial roofing specialists offer a range of materials suitable for keep flat roofs, and the buildings they serve, cool. However, these materials each have their own properties, pros and cons, so make sure to inform yourself of the various choices on offer before choosing a material.
Concrete may seem unwieldy and outdated as a roofing material, but when it comes to keeping commercial properties cool, concrete tiles can really come into their own. Inexpensive to purchase and install, concrete tiles provide excellent heat insulation without sacrificing toughness and durability and are an excellent choice for high security buildings. They are also available in pale, 'cool' colours that reflect sunlight to provide additional protection for heat.
However, concrete tiles are heavy, and smaller pre-fabricated structures may not be able to bear their weight. Using concrete tiles may also violate certain local building codes, particularly in areas where high winds are common, so it's important to consult extensively with your roofing contractor and local building authorities before choosing this option.
EPDM stands for ethylene propylene diene monomer, and while the name of the may be complicated, installing it certainly isn't. EPDM sheets can be stretched and fitted into place with ease, and since they only require gluing or nailing down, they can be installed by professional roofers in a matter of hours. The flat, smooth roof that results can stand up to most everything the weather can throw at it, and the EPDM itself is impregnated with special chemical compounds to prevent it perishing in the sun like conventional rubbers. When it comes to heat resistance, ordinary EPDM roofs can provide adequate insulation, but special light-coloured versions are available for hot weather roofing. If this is unavailable to you, most EPDM roofs can be effectively coated with radiant barriers or reflective overlays to increase light reflection.
Unfortunately, while EPDM is robust enough to tolerate a beating from nature, it doesn't stand up too well to human vandalism and burglary, and EPDM roofs provide little in the way of physical security. Because they are watertight, they can also present problems with internal humidity, as ambient moisture is no longer allowed to escape buildings via the roof. This can cause problems with mould and make the interior of a building unpleasantly clammy without adequate ventilation.
Conventional roofing bitumen is an excellent heat insulator, but its dark colouration means that it absorbs far more heat than it reflects -- hardly an ideal choice for hot weather roofing. Modified bitumen, however, has far more going for it -- this modern cousin of bitumen is available in a wide variety of pale shades to maximise heat reflection, while providing the same excellent heat insulation to reduce heating bills in winter and air conditioning costs in summer. Modified bitumen is laced with fibreglass and polyester fibres to increase its durability, and unlike traditional asphalt, it can be fitted with conventional cold adhesives rather than torching, allowing the building in question to be occupied and used during the roofing process.
However, modified bitumen is significantly more expensive than conventional bitumen roofing, and can be more difficult to find than more common roofing materials. It is also vulnerable to certain chemical corrosives that can cause pitting and shorten the bitumen's lifespan, such as acid rain and bird guano.