Materials & Profiles
Choosing a new metal roof involves more than picking a colour. The roofing product, the profile, the steel thickness and the property's exposure all affect how the roof should be specified. We install COLORSTEEL® and COLORCOTE® roofing systems across Auckland, and help you settle on a combination that suits the property, the roof design and the location.
The coated steel the roof is actually made from, such as COLORSTEEL® or COLORCOTE®. That's the product itself, separate from the colour you pick.
Called the profile. It's the shape the flat sheet is rolled into, and it's what gives the roof its look: classic corrugate, wider ribs, or flat trays with raised seams.
Sometimes called the gauge. It's usually described as 0.40 gauge or 0.55 gauge, and it shows on your quote. Thicker steel stands up to knocks and denting better.
Your property's location determines its exposure zone, most commonly whether it's coastal or non-coastal. That decides which version of the product is specified, since a house in salt air needs more protection than a sheltered inland site. We'll tell you which applies to your address.
Looking for colours? View COLORSTEEL® and COLORCOTE® roofing colours
The traditional curved profile used on New Zealand homes for generations. It suits classic and character houses, and it's available across every supplier we use.
A defined rib pattern that spans further than corrugate and carries more water, which suits larger roof areas and lower pitches. It works on contemporary and traditional homes alike.
Wide flat pans between tall ribs, usually secret-fixed with concealed clips. The flat pans give a modern look and the profile handles large volumes of water.
The broad category: wide flat pans separated by raised seams, used on roofs and on wall cladding. It covers a number of systems, including roll cap and angle seam, each with its own seam detail and look.
Flat pans joined by a raised vertical seam, folded or snapped together. Systems such as Eurotray sit in this group. It suits roofs and cladding where the seam lines are part of the design.
Systems where the clips sit under the seam rather than through the face of the sheet, such as Spanlok. Nothing pierces the visible pan, and the sheet can move as it expands and contracts.
Which exposure zone you're in. Coastal, geothermal or inland changes the material we recommend and the warranty that comes with it.
Low-pitch roofs need high-rib profiles so water can't get in through the side laps. High-rib and trough profiles also span the furthest, which suits commercial buildings. Standard profiles suit steeper pitches.
A commercial roof carrying regular foot traffic and point loading has different requirements from a house, a small lean-to or a deck roof.
Classic corrugate, defined ribs or flat trays with standing seams. What you want it to look like narrows the options, within what the roof itself allows.
There are different grades of roofing material, each designed for a different exposure zone, and each carrying its own warranty period. The full details are on the COLORSTEEL® and COLORCOTE® websites.
New Zealand Steel's current single product for most environments, from mild and inland through to very severe coastal. It uses a zinc, aluminium and magnesium coating for added corrosion resistance, and replaced the older ENDURA® and MAXX® products.
Specified where the environment is extremely severe, such as heavily exposed coastal sites or aggressive industrial areas, where MAXAM® isn't the right choice.
A zinc-aluminium coated steel for moderate environments, away from heavy salt spray or industrial exposure.
For more demanding environments, including coastal exposure, where the roof needs greater corrosion protection.
An aluminium option for very severe marine, industrial and geothermal environments.
A fleece layer bonded to the underside of the roofing, which helps manage condensation. Generally specified on commercial buildings to avoid the need for underlay.
Not sure which applies? Tell us the address and we'll confirm the exposure zone for the property, the grade that suits it, and the warranty that comes with it.
The warranty on your roof is determined by several factors, including the exposure zone, the roof pitch, the roof colour and the product grade. Depending on the product and the environment, material warranties can run up to 50 years. Both manufacturers publish their current terms and warranty periods on their websites. We check the warranty period at the quoting stage, so you know what yours will be and have the chance to upgrade if you want to. Once the job is finished, we hand over the supplier warranty documentation and the maintenance schedule.
Warranty periods depend on the exposure zone, the roof pitch, the colour and the product grade. Check the current COLORSTEEL® warranty terms.
Warranty periods depend on the exposure zone, the roof pitch, the colour and the product grade. Check the current COLORCOTE® warranty terms.
Tell us the property and what's on the roof, and we'll work out which warranty applies and what it covers. Ask us about your roof warranty.
Frequently Asked Questions
It depends on the property's location, its exposure to salt or other corrosive conditions, the roof design and the type of building. For many Auckland properties a standard pre-painted steel system is suitable. Homes in more exposed coastal locations may need a product with greater corrosion resistance, and extremely severe environments may call for an aluminium-based system. We look at the property and its exposure before recommending a product, rather than picking on brand or colour. Both the COLORSTEEL® and COLORCOTE® ranges include products designed for different environments.
It depends on the design of the house, the roof pitch, the look you want and what the roof technically needs. Corrugate gives the traditional New Zealand look. Trapezoidal or T-rib has stronger, more defined ribs and generally carries more water and spans further. Trough, tray and standing seam give a cleaner architectural appearance and can use concealed fixings. You don't have to choose on appearance alone: we make recommendations based on the manufacturer's specifications, which cover things like minimum roof pitch and performance, so you know which profiles will work before you make the visual call.
Gauge refers to the thickness of the base metal the sheet is formed from. For long-run steel roofing, 0.40 and 0.55 are both commonly used, but they aren't interchangeable in every situation. The right thickness depends on the profile, the wind zone, the supporting structure and how much foot traffic the roof is likely to get. The 0.55 material stands up better to foot traffic and is generally used where more robustness is needed. A thicker sheet isn't automatically the right answer for every house; the specification has to work as a whole.
Possibly. Coastal exposure is one of the main things we consider. Salt in the air increases the risk of corrosion, so a property closer to the sea or in a more exposed spot may need a product with greater corrosion protection than a sheltered inland home. COLORSTEEL® MAXAM®, for example, covers environments from mild and inland through to very severe coastal, with ALTIMATE® for extremely severe conditions. COLORCOTE® works the same way through ZinaCore™, MagnaFlow™ and AlumiGard™. When we quote your roof, we apply to the suppliers for your property and come back with the options, so the warranty period for each and what it costs are both on the quote from the start.
A roofing system is more than the sheet you see from the street. We work through the material, the profile, the thickness, the coastal and corrosion exposure, the roof pitch, the purlins and structure underneath, the wind zone, drainage, how the roof will be accessed for maintenance, and the appearance you want. The aim is a system that suits the building and its environment, rather than components chosen in isolation. Impact Roofing Solutions quotes name the product and the profile being proposed, so you know exactly what has been specified.
Often, yes. A reroof is a chance to change from one profile to another, for example from corrugate to trapezoidal. The new profile still has to suit the roof pitch and follow the manufacturer's specifications, and the structure it's fixed to has to support it, which means the purlin spacing needs to be right for that profile. We assess the substrate to see whether anything needs altering so the finished roof is compliant, then tell you which profile options are practical for your property before you decide.
Because not every product is designed for the same environment or the same job. Warranty length depends on a range of factors: the grade of material, the paint system, the corrosion zone the property sits in and how close it is to salt water, the roof pitch, which affects how quickly water runs off into the gutters, whether the material is used as roofing or wall cladding, and the gauge of the roofing itself. Together those determine how the material performs. The manufacturer sets its own terms, which have to be followed, and the supplier has its own terms and warranties on top of that. Our job as the roofer is to apply that experience and work out which product suits your roof.
Both are New Zealand brands of pre-painted metal roofing, but they offer different product ranges, coating systems and environmental options. COLORSTEEL® currently offers MAXAM® for most New Zealand environments and ALTIMATE® for extremely severe conditions. COLORCOTE® offers a tiered range: ZinaCore™ for moderate conditions, MagnaFlow™ for more demanding environments and AlumiGard™ for very severe marine or corrosive environments. Neither is automatically right for every property. We look at the roof design, the location and exposure, the profile options, the colour you want and the warranty that applies before recommending one.
Get in touch with us. We'll work out whether it's a workmanship issue or a defect in the material, and then guide you on what the remedy is and how it gets sorted.
In many cases, yes. Manufacturer, supplier and workmanship warranties can usually be transferred to the new owner, but a process has to be followed. You need to notify the company that completed the work that the property is changing hands, and the completion certificate needs to be addressed to the new owner. The terms don't start again: what transfers is the remainder of the original warranty period. Every company handles it slightly differently, so it's worth asking how their process works during the quoting stage.
A long-run steel roof generally lasts decades, but how long depends on the product grade, the exposure zone, how well it's installed and how it's maintained. The manufacturers set their warranty periods on the same basis, which makes the warranty a reasonable guide to what to expect. Ask whoever is doing the work what their workmanship warranty covers, and check the supplier's warranty period for the product being used.
Where we can, we use New Zealand-made materials. Both COLORSTEEL® and COLORCOTE® are manufactured here in New Zealand and developed for New Zealand conditions, backed by their own warranties. Their websites set out the current warranty terms, and there are links to both further up this page.
