ContentsThe use of galvanizing for structural steel protection gives you measurable benefits:
1. Lowest first cost.
Galvanizing is lower in first cost than many other commonly specified protective coatings for steel. (The application cost of labour intensive coatings such as painting has risen far more than the coast of factory operations such as galvanizing - in the past ten years the labour component of finished paint coatings averages about 90%, compared to only about 20% or even less for galvanizing.) The graph speaks for itselft.
2. Less maintenance / Lowest long term cost.
Even in cases where the initial cost of galvanizing is higher than alternative coatings, galvanizing is almost invariably the cheapest in the long term (because it lasts longer and needs less maintenance). And, maintenance causes problems and adds to costs when structures are located in remote areas, and when plant shutdown or disruption to production is involved.
3. Long life.
The life expectancy of galvanized coatings on typical structural members is far in excess of 50 years in most rural environments, and 20 to 25 years plus, even in severe urban and coastal exposure.
4. Reliability.
Galvanizing is carried out to Standards 1460 & 1461, and standard minimum coating thicknesses are applied. Coating life and performance are reliable and predictable.
Galvanized coatings are thicker at corners and edges, a major advantage.
Organic coatings thin out in these critical areas.
5. Toughest coating.
A galvanized coating has a unique metallurgical structure which gives outstanding resistance to mechanical damage in transport, erection and service.
6. Automatic protection for damaged areas.
Galvanized coatings corrode preferentially to steel, providing cathodic or sacrificial protection to small areas of steel exposed through damage. Unlike organic coatings, small damaged areas need no touch up.
Galvanized test piece has had areas of coating removed before exposure to severe industrial environment. Sacrificial protection prevents corrosion of circles up to 3 mm diameter, minimises corrosion of 5 mm circle.
7. Complete protection.
Every part of a galvanized article is protected, even recesses, sharp corners and inaccessible areas. No coating applied to structure or fabrication after completion can provide the same protection.
8. Ease of inspection.
Galvanized coatings are assessed readily by eye, and simple non-destructive thickness testing methods can be used. The galvanizing process is such that if coatings appear sound and continuous, they are sound and continuous.
9. Faster erection time.
As galvanized steel members are received, they are ready for use. No time is lost on-site in surface preparation, painting and inspection. When assembly of the structure is completed it is immediately ready for use, or for the next construction stage.
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