There's a lot to consider when undertaking a re-roofing project but making a smart choice has never been easier.
The perfect roofing material is about a lot more than good looks and affordability.
Environmental factors such as location, increasing incidents of extreme weather, roof design, durability, and maintenance requirements all need to be considered and if the household’s water is to be collected from the roof, it’s important to check it will be safe to drink.
Think long-term; while some products may seem expensive initially, by taking their lifecycle costing into account, they may ultimately be one of the cheaper options.
That said, poor workmanship can lead to failure of any roofing material. Always check the credentials and expertise of an installer and make sure you’re comfortable with both the product and installation warranties. (By law the minimum durability expected for roofing is 15 years).
A huge number of variables affect costs; prices quoted are a guide only, include installation, and are GST exclusive.
Today’s metal roof is a far cry from the corrugated iron that roofed homes for decades; but long-run metal, with either pre-painted steel or aluminium substrates, is still our most widely used roofing material.
It’s a look that doesn’t date. Different levels of paint finish provide for different environmental and climatic conditions and guarantee years of trouble-free wear.
A metal roof is strong but comparatively lightweight and can be installed in a shorter time frame than other roofing materials.
Options include fixed-through sheeting and clip-on roofing. Costs for long run roofing range from around $56 per square metre.
Metal also comes with the look of traditional tiles and shingles; Gerard Roof’s aluminium-zinc coated steel tiles are similar in price to long-run iron – and cost considerably less than concrete roof tiles. With UV protection technology and light-fast pigments, they ensure a roof that looks good and “performs without fault” in all living environments, says Craig Wilson.
The fact there’s no necessity for special coatings or fastenings, even in areas subject to extreme conditions, is another plus, he says.
$50 - $70 per square metre
With a wide range of colours and profiles available, concrete and clay roof tiles can highlight both traditional and contemporary house designs. Even after years of exposure to the elements, terracotta roof tiles will retain their colour.
Tiles are also durable, performing well in high wind-zone areas and coastal locations; they won’t rust, warp or corrode, will reduce heat loss and provide an effective barrier against noise.
However, concrete and clay are not lightweights so it’s important to check the strength of trusses. Tiles may need occasional spraying to prevent growth of moss and lichen.
Concrete from $75 per square metre
Clay from $104 per square metre
“Quarried slate has been labelled ‘the gold standard’ in roofing materials,” says Nik Pudney at Natural Roofing Products.
“Quality slate, installed correctly, will give you 100 plus years of service. It’s impervious to UV damage, salt spray, acid rainfall and damage from the snow and ice.”
But, at around 38kg per m2, slate is a roofing heavyweight, so the structure below needs to provide appropriate support.
Nik advises consulting a structural engineer before opting for slate roofing. Quality is also important; a reliable supplier will provide certification.
There are huge variables in pricing – quarried slate is dearer than many other options, but the reliability and stability more than justifies the cost, says Nik.
From $300 per square pmetre
A centuries-old roofing solution, copper is probably one of the best choices for many parts of New Zealand, says Mark Hallt of Architectural Metalformers.
“It’s good looking, durable and malleable and a lot more impervious to corrosion and breakdown; probably one of the best products you can put on the coast.
“The only downside is the need for an occasional clean down where there’s driving sea-spray and not a lot of rain.”
From around $190 m2 + GST for a low mono-pitch roof, copper is not a cheap option – but when it can last 200 years, that’s great value.
From $190 per square metre
Waterproofing membrane roofing systems, most commonly used in flat roof situations, include products ranging from two layer bitumen membranes through to single-layer rubber or plastic membranes and liquid coating systems.
Choose a product with a history of use in New Zealand, says John Simmons, MD at Nuralite Waterproofing. “Our UV and conditions can challenge successful international solutions.”
And, when weighing up the merits of repair against replacement, John says repair is often problematic. “Merely coating a product over a failed system can lock the problem in – mould will continue to grow in damp conditions.”
He gives a $100 per sqm as an approximate price but it varies depending on the size of the job, location, complexity or detailing required.
From $100 per square metre
When you’re looking for kerb appeal, cedar shingles and timber shakes are hard to beat, says Natural Roofing’s Nik Pudney.
“No two pieces are identical so a unique look is created every time, and they can be manipulated through all types of architectural curves and corners giving renovators a vast range of design options.” Cedar can also be stained or painted.
Cedar is a sustainable source, which can help insulate more efficiently than other products, reducing energy costs. With careful consideration to location, climate and home surroundings, cedar shingles and timber shakes can last up to 10 years longer than other products.
From $160 per square metre
Imported asphalt roof shingles provide a strong but lightweight roofing system that’s resistant to salt, UV and mildew in a wide range of colours for great street appeal. It’s worth opting for top quality asphalt shingles that carry a 20-year algae-free warranty and a 15-year wind warranty, transferable to new owners if a house is sold.
From $55 per square metre
If you would like to discuss roofing options and ideas for your next renovation project, please use the enquiry form on this page to provide us with your contact details. We will get in touch with you at a time that suits you to discuss your project. If you would like to provide us with more information about your project, we have a more comprehensive enquiry form on our "Get in touch" page too.
*Costs are rough estimates and are subject to change. For a fixed-quote accurate to your specific project, please consult your local Refresh Renovations specialist. All Refresh Renovations franchises are independently owned and operated.
All Refresh Renovations franchises are independently owned and operated.
If you would like to find out how Refresh Renovations can support you with a high quality, efficient home renovation, get in touch today. Your local Refresh Renovations consultant will be happy to meet with you for a free, no obligations consultation.