BUILDING: Blue-Chip Roofing Advice
Recent Western Cape Business News
MANY commercial property owners are not getting the fairest deal for their Rands when roofs are fitted to new developments or replaced during renovation work on buildings.
Multinational roofing material supplier, BlueScope Steel, which restarted trading in South Africa during 2007, has surveyed the usages of various grades of galvanised and pre-painted steel roofing materials. The results show a concerning lack of knowledge and information among many contractors and roofing system suppliers as to the effectiveness of the various types of steel roofing materials. According to the company’s Wayne Miller, “We observed a great deal of non-compliance with minimal design standards”.
Customers should be aware of being supplied cheaper low coating mass products (Galvanised Z160 or Z200 or Aluminum / Zinc AZ100) in a market where corrosion is an issue of serious concern up to 5 km from the coast line. Most suppliers would recommend a Galvanised Z275, or Zincalume AZ150 to ensure building durability and performance through its life in this environment
According to Miller, this practice is highly prejudicial to the rights of the client and sadly the issue has gone by largely unchallenged in recent times. “With the worldwide swing to sustainable building practices, roofing systems should provide the owner with optimum levels of performance and lifespan.” In the view of BlueScope Steel, sustainable means:
• Long life and ultimately recyclable
• Less material usage in the coating – lower coating mass = better performance
• Thermal efficiency and heat reflective.
“BlueScope Steel believes South Africa can ill-afford the ongoing cost of maintaining and replacing roofs that should give many years of service, provided materials used meet architects and manufacturers’ standards. We urge developers to monitor what is happening on site to ensure that materials used are the same as those that are specified”, Miller says.
Along the South African coastline, for example, where climatic conditions are harsh within the 5 km zone, Miller and his team have encountered building projects where steel roofing is failing after just 5 years. “It is clear that the Z160 and Z200 coating mass of galvanised or pre-painted galvanised steel has been used, against the manufacturer’s own advice.”
“We recommend only premium grades of alloy-coated steel such as Zincalume and pre-painted steel such as Clean Colorbond, all manufactured with a 55% aluminium, 43.5% zinc and 1.5% silicon coating (AZ150 coating) be used within 5 km from the coast line or under normal circumstances.”
“If you are building within 100 - 200 metres of the water, we would advise using our Clean Colorbond Ultra, which has an AZ200 coating – in this case coated to a mass of 200 g/m2 over the steel substrate. This is also particularly useful in severe industrial environments, where there are aggressive fumes or particulate fallout within the 200 meter radius.”
“In addition, the high performance paint system on Clean Colorbond incorporates various sustainability features such as high reflection of incoming solar radiation, exceptional colour retention, anti-chalking and dirt resistance”, he adds.
BlueScope Steel products, Zincalume and Clean Colorbond are covered by a manufacturer’s warranty of performance when correctly installed. Miller says that the warranty is subject to terms and conditions and it is important that clients contact the BlueScope Steel office prior to commencing works on the roof. “Correctly used, our product should give a lifespan up to four times longer than the standard galvanised steel”, he says.
Identification of BlueScope Steel product is easy. Each panel of formed roofing material has been uniquely branded on the undersurface, thereby avoiding any confusion.
Business News Sector Tags:
Fax 2 Email
Study IT Online
Work from Home