There are so many reasons to choose metal roofing on your house. It’s a classic look and highly durable, especially in harsh New Zealand conditions. And who doesn’t love falling asleep to the sound of raindrops on a tin roof? Of course, with metal roofing, you need to be careful if you live anywhere near the coast. The sea spray contains salt and other electrolytes than can oxidise metals, leading to corrosion. And there’s also that wicked coastal wind to consider. If you’re planning to put up a metal roof on your coastal property, make sure you do it the right way. Follow these five tips for guaranteed success and a roof that will stand the test of time.
Watch out for galvanised steel
While galvanised steel is normally a durable and resistant roofing material, it won’t always stand up to the harsh coastal conditions encountered in New Zealand. Galvanising refers to the process of dipping the steel in hot zinc to provide a coating that resists corrosion. The zinc is more chemically active than steel, so corroding agents in sea spray react first with the zinc before it corrodes the steel itself. However, tests show that ordinary galvanised steel doesn’t stand up to the elements in practise. This is especially true if the steel contains chromate, an especially susceptible material to corrosion. For the harsh New Zealand coastal conditions, better coatings are needed.
Look for specialised roofing metals for the coast
Luckily enough, there are several roofing metals that do a better job resisting corrosion. Zincalume incorporates silicon and aluminium into its protective coating as well as zinc. This increases the protection and adds a barrier layer to provide protection in addition to the sacrificial effect of the zinc. In tests, Zincalume far outperforms regular galvanised steel in resisting sea spray. Other products called Endura and Maxx offer similar protection, and which one is ideal for your home depends on specifics, so talk to your roofer to find out more.
Consider a waterproof membrane
Sometimes, no metal alone will be enough to resist the elements. You might want to consider a waterproof membrane coating on your roof to seal it against the sea spray. These membranes are typically based on either fiberglass or bitumen. Roofing and Coatings uses the industry-standard product based on each material. Traffigard membrane is a fiberglass coating based on the latest technology. It is quick-drying and available in a wide range of colours. Meanwhile, Nuraply is a bituminous coating that incorporates a reinforcing polyester layer. Either of these coatings will protect your roof for years, leaving you worry-free.
Look out for the wind
When considering adding a metal roof, it isn’t just the sea spray you need to watch out for. Any New Zealander will tell you that our coastal areas can get windy – very, very windy. Wind damage to roofing is actually one of the most common classes of property damage worldwide, so it should not be taken lightly. There are several different kinds of metal roofing, and some resist the wind better than others. Ask your roofer about single seam roofing – this has proven to be the most wind-resistant way to install a metal roof in tests and in practise. The roofer also needs to adjust the spacing between the fasteners to suit the pitch of your roof to ensure maximum wind resistance, or the whole roof can lose strength.
There’s no substitute for a quality job
You can get all the products you want, but in such an exposed environment as the seaside, you need experienced professionals to install your roof for it to last. Shoddy workmanship can undermine the integrity and lastability of your roof. It only takes one exposed spot for rust to take hold, while a roofer who doesn’t customise their installation to suit the pitch of your house is going to sacrifice potential wind resistance. When selecting your roofer, go with reputation and experience.
Put your roof in safe hands
If you want your metal roof to go the distance in New Zealand’s coastal conditions, then talk to the people who’ve been installing them for over 20 years. Coastal conditions don’t get much harsher than in the region around Wellington and Wairarapa, and that’s where we operate – so it’s safe to say we know what we’re doing. We’re a member of the Roofing Association NZ and Site Safe NZ, so you can also be assured we do things the right way. We do free inspections and quotes, so get in touch with us now to talk about your specific needs.