THE MAGIC FORMULA:
55% Al-Zn METALLIC COATED STEEL PROVED THE OUTSTANDING STEEL CLADDING
SUBSTRATE IN 10-YEAR COMPARATIVE TESTS
An independently-observed series of 10-year comparative trials of three different steels as substrates for pre-painted cladding has shown that 55% Al-Zn metallic coated steel delivers truly remarkable corrosion resistance.
In co-operation with the European Coil Coaters Association, the EuroZAC association of manufacturers of 55% Al-Zn metallic coated steel carried out the exposure test programme to provide specific European performance data.
Tested for the first time in Europe against Zn-5% Al (Galfan ®) and hot-dip galvanised substrates, the results conclusively show that 55% Al-Zn provides superior performance.
Two sites, one in a severe marine environment at Hendaye in France and the other in an inland industrial environment at Geleen in The Netherlands, were approved and monitored by ECCA to their T-19 standard. At both sites, panels were exposed in three configurations – including a low south-facing slope to represent roof areas, and a north-facing side wall aspect with an overhang to represent sheltered area conditions.
After ten years’ exposure, the panels were sent to an independent laboratory and evaluated for corrosion resistance along flat and formed areas, overlapped joints, along scribes and unprotected sheared edges, and around fasteners.
The results of the panels exposed at 5º south, the severest test, particularly indicate the unequalled durability of 55% Al-Zn substrate for roof applications where long trouble-free life is essential.
For more details, click here.
UNPAINTED STEEL ROOFS SET TO LAST 40+ YEARS WITHOUT MAJOR MAINTENANCE
European building survey proves corrosion resistance of aluminium-enriched zinc coating
Modern roof systems like standing seam have made low-pitch steel roofs a practical and economic answer for office, leisure, retail and industrial buildings. Yet the problems of corrosion, even with pre-painted steels, have pushed up running costs because of the need for complex preventative maintenance programmes to prolong the life of the system: pre-painted roofs, for example, frequently need overpainting after as little as 10-15 years.
Now a Europe-wide building survey shows that even unpainted steel roofs can deliver a life of 40 years or more before major maintenance. Provided that the steel is protected with the 55% Al-Zn aluminium-enriched zinc metallic coating.
Developed some 40 years ago, and known in Europe under the brand names Aluzink ® (Groupe Arcelor), Aluzink ® (SSAB) and Galvalume ®, 55% Al-Zn coated steel has steadily built an impressive record in roofing, both for new build and retro-fit applications. Though initial acceptance in Europe lagged behind that of the USA and Australasia, 55% Al-Zn sheet has increasingly become a first choice for roofing specification, with European production running at around 700,000 tonnes in 2002.
"The astonishingly long unpainted performance is confirmed by the European Field Inspection Survey: 55% Al-Zn can confidently be expected to last over 40 years before major maintenance.
For full report on the survey, click HERE."
11% INCREASE IN WORLD PRODUCTION OF 55% Al-Zn STEEL
The versatile 55% Al-Zn coated steel grew by a further 11% in 2002, following a 15% leap the previous year. Independent accountants report that global production has now reached some 5.5 million tonnes.
This growth is all the more remarkable given the generally sluggish world economic environment. Growth is being driven by the material’s outstanding performance on roofs, especially when left unpainted.
Performance is confirmed by the first phase of a European
survey (see story below, and detailed
report).
The second phase of the survey has now been completed, and the results will be published here shortly.
55% Al-Zn METALLIC COATED SHEET WINS U.S. ENERGY STAR®
Unpainted 55% Al-Zn coated steel meets the cool roof
requirements of the United States Environmental Protection Agency (EPA)
ENERGY STAR® Roof Products Program.
EPA says: "Reflective roof products save consumers money. By installing
a reflective roof product, the exterior solar reflectivity of a building
is increased, thereby lowering roof temperature, decreasing the amount
of heat transferred into the building's interior and ultimately reducing
the amount of energy needed, and money spent, to maintain comfort inside."
For more information about ENERGY STAR® visit www.energystar.gov
55% Al-Zn IN SWEDISH LABORATORY
The roof of this laboratory at the university of Uppsala, Sweden, forms part of a Faraday cage, protecting sensitive equipment from electromagnetic disturbance.
The architects rejected copper sheeting because of potential problems with surface water run-off. Titanium zinc was too expensive, and can only be erected at certain temperatures.
But 55% Al-Zn Aluzink steel from SSAB Tunnplåt was equivalent in appearance, much more cost efficient, and easy to work with.
55% Al-Zn ROOFS AWARD-WINNING STATION
- The dramatically soaring roof of the new Olympic
Park Station in Sydney, Australia, owes its success to 55% Al-Zn steel.55%
Al-Zn at the Millennium Olympics
- The dramatically soaring roof of Olympic Park Station,
gateway to the Millennium Olympics in Sydney, Australia, is made from
55% Al-Zn steel.
- Architect Ken Maher, of Hassell Architects, says:
"We used it with no paint finish... we wanted to express all the
materials very directly and very honestly.
- 55% Al-Zn is the first steel specially developed for roofs.
