Stainless Steel in Coastal Environments

Can Stainless Steel Rust?

The process of corrosion, or more commonly known as rust, is the destruction of materials by chemical reaction. Stainless steel, although highly resistant to corrosion, has the capability to rust depending upon the grade of the steel and the environment it is in.

Two main forms of stainless steel rust are pitting corrosion, resulting in small holes in the metal, and crevice corrosion, occurring at the gap between two surfaces. These forms can cause structural damage to the steel and weaken the metal, reducing the lifespan. Another common form is the act of tea staining, which is the discolouration of the stainless steel. Tea staining does not impact the structural form of the stainless steel but only the cosmetics and is most common near coastal environments.

With beautiful views and amazing environments, the coast is a popular place to build a family or holiday home. This creates a concern on the structural materials (mainly steel) needed to build a strong, sustainable home. As previously stated, stainless steel is the most resistive to potential corrosion from the salty air near the coast and therefore the best option for your future beachfront home.

The higher the grade of the stainless steel, the better protection against rust but at a much higher cost. According to Australian Standards, lower grade steel can be used in seaside environments as long as it has been treated by painting or surface staining.

COLORBOND Steel

iBuild uses COLORBOND or equivalent for a variety of steel purposes within their homes. COLORBOND stainless steel is grade 430 with a corrosion inhibitive coating on both sides of the metal. This coating follows AS 2728 and 1580 standards.

COLORBOND recommends Stainless Steel roofing for areas within 100 metres from ocean and Ultra Steel for roofing over 100 metres from ocean. For walling, Stainless Steel is recommended for up to 500 metres and Ultra Steel from 500 to 1000 metres. The warranty calculated from BlueScope for this product is stated below depending on purpose and distance to a surf zone, or the ocean coastline. This warranty does not cover earthquakes or typhoons or any other similar extreme “acts of god” or damage done by improper construction, transport, or maintenance care from the owner.

Steel Warranty based on Bluescope Products

Stainless Steel based on distance from Surf Zone

	0 m	1000 m	5000+ m
Roofing	25 years	30 years	36 years
Walling	12 years		15 years
Eave, Gutters, Fascia, Downpipes	25 years

Ultra Steel based on distance from Surf Zone

	0 m	100 m	300 m	500 m	1000 m	5000+ m
Roofing	10 years	15 years	20 years	25 years	30 years	36 years
Walling				12 years		15 years
Eave, Gutters, Fascia, Downpipes		12 years
Garage & Sheds		10 years		15 years