Testing and experience in the roofing industry has shown that metal roofing products are very susceptible to sea water and if they are too close to the ocean – corrosion will occur. Though not all metal roofs will corrode at the same rate, over time, the salty sea air and the humidity will react on metal roofing and it will deteriorate. But metal roofing material has undergone a sea-change and current-day metal roofs have different types of coatings which can prevent them from getting as affected as uncoated metal does.
Steeling Structures From the Salty Air
Australia has a lot of coastland and finding a good roofing product which will be suitable can be a challenge. But galvanized steel is definitely not recommended for structures close to the ocean. The salt air will eat right through the material and you will be stuck with re-roofing the entire structure within a matter of years. But materials such as aluminium, lead (atmospheric), copper (in air & moisture), ter-coated stainless steel and stainless steel are all considered to be “corrosion resistant materials”.
If you have a home or any other structure in the coastal areas, the roofing material will have to be highly corrosion-resistant. In addition, it has to be able to resist wind-uplift. This is why standing-seam metal roofing is an ideal choice for these areas. A number of current-day metal roofs are guaranteed to be able to withstand winds of upto 120 miles/hour and most are also corrosion resistant.
When they are properly installed, most high-grade stainless steel roofing materials that are coated with alloys are made of a zinc and tin mixture. These are the ones that provide the highest levels of corrosion & condensation resistance possible. Certain other alloys and coated-over metals such as copper, aluminium and zinc are also able to provide more corrosion resistance and they can easily pass 2,000-3,000 hours of salt-spray testing.
What to Avoid
If you want your roof to last longer, then avoid using galvanized roofing that has chromate in it. This material is more prone to water wash-out and corrosion, and will not last long. But roofing technology is changing and there is continuous improvement in the testing standards & awareness of the actual quality of materials that are used to coat and treat metal roofing. Using higher quality metal roofs that have strong and lasting coatings helps in preventing corrosion.
Though living in coastal areas is an attraction, roofing problems can make homeowners question their own decision. Apart from the corrosion, they also have to sometimes deal with hurricane-force winds, and installers also have to pay attention to installation methods. All roofing materials manufacturers have recommended installation procedures for all their products and these should be followed to the tee when the metal roof is being installed.
A Better Option
Polyvinylidene fluoride/PVDF coatings that are manufactured from certain resins are considered to be the best coating for all kinds of metal coatings and brands like COLORBOND® steel are being used for roofs across Australia. These are long-lasting, strong and low-maintenance, and more importantly, they resist corrosion. But it has to be understood that even the highest-quality polyester paints will not be able to survive for decades in sub-tropical and humid environments and a certain amount of chalking and gloss-loss will occur.
The Smart Decision
If you are trying to decide which material you need to use on your home/ any other structure close to the sea and are zeroing-in on metal roofing, look for ones that have SPF Coatings which will be able to withstand aggressive marine and saltwater environments. Some of these roofing materials that have been specially treated may be heavier on the pocket, but they will last much longer.
The vast ocean is what lends it allure to Australia and its difficult not live near it. And so, if you are in a “roofing” quandary, are looking for a strong material that will be able to withstand all the humidity and gales, don’t give metal roofing a miss – just find the ones that are coated right. For more information about whether metal roofing is the right choice for you, connect with RO Steel Roofing on (02) 9660 5937.