Salt & Water Erosion: Kiwi Climate vs. Metal Roofing

April 28, 2020 at 2:08 PM

Choosing the right material for roofing in Auckland requires a lot of consideration, and not just because we’re a stylish city. As an island nation, New Zealand enjoys the salt in the air and the rainy periods that give us such amazing seasons, but these are also factors in choosing the right roofing material.  

Corrosion is a real problem in Aotearoa, where humidity, rain, and salt all gather to push metal roofs to their limits. This is one of our primary concerns as a roofing company, and in this blog post we’re going to reveal how we address it when re-roofing our clients’ homes.  


Oxidization: How Water and Salt Affect Metal Roofs 


Some science every now and then is good for the soul, but don’t worry, we won’t go too deep into the theory. Oxidization is just a fancy word for when things react with oxygen, and in metal this causes rusting and weakening.  

The basic principle of oxidization is a trading of electrons, the little zippy things that carry charge around an atom. Metals don’t usually react with oxygen at all, but when water is introduced into the mix it breaks up the oxygen molecules present in the metal. This allows the electrons to run free, escaping into the air and causing the metal to change its composition. The metal goes orange and starts to flake off, revealing the untouched roof beneath.   

In salty environments, this process is accelerated. Saltwater is more reactive and lets electrons travel through it faster. Therefore, metal roofs in coastal environments are prone to rusting quickly due to all the salt in the air!  


Which Roofing Material Combats Rusting? 

Let’s imagine you’re situated close to the beach and you’re looking to re-roof your home. The threat of saltwater seems too big to handle, and you’ve essentially resigned yourself to a life of roofing and re-roofing your rusted metal roof every three years. Oh, the horror!  

Luckily for you, that doesn’t have to be your reality. We are huge proponents of COLORSTEEL roofing because it’s the best solution for Kiwi homes, no matter where they’re situated. They have several ranges, each one suited to different NZ climates, and all coated with a protective zinc-aluminium alloy (Zincalume) that prevents corrosion.   

The zinc in this coating is sacrificial. It gives its ions away a little bit at a time, reacting with the air before the air can touch the steel beneath. The aluminium in Zincalume doesn’t rust, so these two elements in conjunction with each other form a hardy coating that protects your metal roof for years. For those extra-tough coastal environments, COLORSTEEL offers the MAXX range that includes a corrosion-resistant primer and a baked-on finish to fight the salty air.   

So, if you’re looking to avoid the unending struggle of rusting roofs, reparations, and replacements, we’ve got your back. 

  

Rely on Auckland’s favourite re-roofers to rust-proof your home  


We’ve been a roofing company in Auckland for many years, so we’re experienced in finding the right roofing solution for our clients’ individual needs. Get in touch with our team today and weatherproof your home against everything the Kiwi climate has got.