Most residential / commercial buildings are primarily of bricks or concrete but require the strategic use of steel for the critical linkage, strength and anchorage required within building systems.
The Australia / New Zealand Standard series AS/NZS 2699:2000 Built in Components for Masonry Construction, specifically covers such items and addresses their reliable and proven durability.
• Wall ties
• Connectors and accessories
• Lintels and shelf angles
These Standards have been revised as a reference to the masonry code AS 3700, during upgrading of the relevant codes mandated after the Newcastle earthquake.
Steel corrosion protection for 50 years is a code requirement to ensure safety, prevent brick or concrete cracking as rusted steel volume expands x3 and to avoid the need for maintenance.
Building surveyors are already asked to accept responsibility for judging the exposure severity of the building location, where the codes provide instructions on levels of corrosion severity from R0 to R5.
Protective coating systems in the Standards, range from grit blasting and 3 coats of high performance paint APAS (formerly GPC) approved, to hot dip galvanizing or stainless steel. However it appears that in some States the commonest treatment is one coat of general purpose primer with a protective life of 2-5 years.
Thus such steel work may seem in order for 6 years or so but there after give rise to serious structural problems, which in many cases will be covered and unseen until structural failure.
At a time when the cost of insurance cover and an inclination to consumer litigation are increasing, we recommend that building surveyors seek documented proof of compliance, before building certification
After Fabrication Galvanizing the Best Insurance Policy for Steel
Standard AS/NZS 4680 aligned to ISO 1461 offers
• 170 years of use
• Service life of 30 to over 100 years
• Hardness exceeding mild steel
• Alloyed to steel substrate
• Competitive prime cost
• Construction efficiency
• Life cycle superiority