One of the most common questions on most people’s minds when investigating replacing their roof is – how much is it going to cost? While cost is always a factor, it is important not to forget that replacing your roof is an investment in the expected lifetime of the building. This is because your roof protects the structural integrity of the entire home as well as all of its contents.
Choosing the right roofing material about durability, ongoing maintenance and future-proofing. You have to think beyond today and tomorrow and take into account the lifespan of both the building and the roof – yes, there may be cheaper options upfront but are the long term costs going to offset those benefits?
10 Common Factors That Affect The Cost Of A New Roof
How is the cost of your roof calculated? Well, there are a number of factors that will determine the final price. The most important being the type of roof cladding you wish to use, whether this is a like for like replacement or a new type of roofing system – see below for 10 of the most common factors that affect the cost of a new roof.
- Location. The location of your house in New Zealand and how far it is from the main centres will affect transportation costs involved in getting the materials and the contractors to your property over the course of the job.
- Roof Pitch. The pitch or slope of the roofline will affect the required access by contractors. The smaller the pitch, the lower the costs.
- Multi-Level? If your house is multi-levelled, it is going to make replacing the roof a bit more challenging and require extra safety precautions such as scaffolding etc.
- Access. If it is difficult to get the new roofing materials close to the house or remove the old roofing materials, this will affect the time it takes to replace the roof by increasing labour costs.
- Scaffolding Requirements. All roofing contractors are required to provide a safe working environment for their staff. This may include scaffolding, safety nets, ladders, ropes, safety harnesses, scissor lifts, boom lifts,
- Materials. Whether you choose to replace your roof with longrun iron, concrete or clay tiles or another type of roofing material, there will be the associated costs of sourcing and transporting these materials to the site. See below for more information on costs associated with each type of roofing material.
- Complexity. How much detailing is required will definitely affect the cost. Complicated rooflines require much more time and effort to get the job done right.
- Installation Method. The installation method will affect the time it takes and how many staff are required to do the job. This all has an effect on the final price.
- Weather Conditions. Adverse weather conditions are always a significant factor in how long it takes to complete any roofing job. High winds, rain and/or snow are the leading contenders.
- The Existing Roof. If an existing roof needs to be removed, or if the previous roof was tile and you are replacing it with longrun iron, for example, then the costs will reflect the extra labour required to prepare the site.
New Zealand Roofing Materials
In New Zealand, the main roofing materials available are metal tiles, concrete tiles, clay tiles, long-run iron, corrugated iron, and asphalt shingles. You can also source timber shingles, slate tiles and copper roofing too, but they aren’t as commonly used.
1. Long Run Colorsteel
By far the most popular roofing material used in NZ, longrun iron is easy to install, it lasts and lasts and lasts, and it doesn’t date. In addition, longrun iron offers a lightweight roofing option (sought after since the Christchurch earthquakes) with pre-painted purchase options.
How Is It Made?
Colorsteel roofing is manufactured from long sheets of steel. It is formed into different shapes, including trough, corrugated and trapezoidal profiles. While it has gone through various manufacturing transformations over the years, it is currently made using zincalume sheeting with a coated (coloured) surface.
How Long Does A Longrun Iron Roof Last?
In NZ, a properly installed, quality Long Run roof has an expected lifespan of 25 to 60 years.
Benefits Of Longrun Iron
- Highly durable
- Resistant to high winds
- Easy to install (much faster than other roofing options)
- Many different profiles to choose from
- Plenty of different colour choices (able to be matched to joinery colours)
- Very low maintenance
- Relatively lightweight
- Can be installed on all types of roofs
- Long life span with minimal maintenance
- Affordable
- Recyclable (at end of its useful life)
Disadvantages Of Longrun Iron
- Can be noisier during heavy rain
- Prone to denting if hit hard by things like tree branches etc.
How Much Does A Colorsteel Roof Cost?
Options include fixed-through sheeting and clip-on roofing. Costs for long run roofing range from around $60 per square metre.
2. Metal Tiles
If you like the look of tiles but not the cost or the weight – then metal tiles might be the right choice for you. Metal tiles/shingles provide an entirely different look to traditional longrun iron; they can be formed into various shapes and styles. Metal tiles are also often made from coloursteel and come in their full colour range.
How Are They Made?
Metal tile roofing is usually manufactured as panels where it looks like several tiles are joined together to reduce installation times, but it is possible to purchase the tiles singularly. Metal tiles are easy to handle and ??
How Long Does A Metal Tile Roof Last?
Depending on the local weather conditions, the lifespan of a metal tile roof is 20 to50 years.
Benefits Of Metal Tiles
- Recyclable
- Reflects heat
- Lightweight
- Can be installed on top of an existing roof
- Fire resistant
- Easy to install
- Long lifespan
Disadvantages Of Metal Tiles
- Noisy in heavy rain
- Can be fiddly to install
- More joins/overlaps than longrun iron
How Much Do Metal Roof Tiles Cost?
Aluminium-zinc coated metal tiles are similar in price to longrun iron coming in between $60 and $80 per square metre.
3. Concrete Or Clay Tiles
Clay tiles have been around for thousands of years and are thought to have first originated from China. They were a common type of roofing in the early days because of their fire resistant properties and durability. Concrete tiles are similar to clay tiles, they are just made from concrete instead of clay. Concrete and clay tiles have been manufactured in New Zealand since around 1930 -1940 and continue to be manufactured all over the country today.
How Are They Made?
Clay tiles are made from baking moulded pieces of clay at high temperatures, just as you would for other things made from clay, such as pottery. New Zealand clay tiles are usually made from local terracotta clays, with the addition of a clear or coloured glaze, which provides greater protection from wet weather. Common colours of clay tiles here in NZ are white, yellow, orange and brown. Concrete tiles are made from sand, cement, and water, which are then moulded together using heat and high pressures. Today’s concrete tiles are usually designed to simulate the appearance of traditional clay tiles.
How Long Does A Clay/Concrete Tile Roof Last?
Concrete tiles should last for over 50 years, and clay tiles can last for as long as 100 years.
Benefits Of Clay/Concrete Tiles
- Hardwearing
- Fire resistant
- Cost-effective
- Excellent for coastal areas (won’t rust, warp, or corrode)
- Good insulative qualities
- Low noise (good acoustic insulation)
- Made locally, environmentally friendly
- Very long lifespan
- Low maintenance
Disadvantages Of Clay/Concrete Tiles
- Prone to fading
- Moss and mould growth can be a problem
- Can become brittle over time
- Very heavy (reinforced roof framing required)
- Can move around causing leaks if not discovered
- Require regular maintenance (spraying to prevent growth of moss and lichen, recolouring)
How Much Do Concrete And Clay Roof Tiles Cost?
Clay and concrete tiles are more expensive compared to the other roofing options listed here, but for those wanting the specific look and authenticity, they provide a long-lasting roofing option. Expect to pay around $80 per square metre for concrete and from $100 per square metre for clay tiles; plus, don’t forget your roof trusses will cost extra due to the reinforcing needed to carry the weight of the tiles.
4. Membrane Roofing Systems
Commonly applied in commercial buildings, membrane roofing systems are often used on flat or minimal sloping roof situations creating a single layer watertight roof covering.
How Is It Made?
Membrane roofing systems in New Zealand tend to use Ethylene Propylene Diene Monomer (EPDM) rubber ply, thermoplastic, glass-reinforced plastic (GRP) and modified butanol products to create a waterproof roof covering.
How Long Does A Membrane Roof Last?
As with all of the roofing options listed here, the longevity of a roof relies on many different factors but as a general guide, you should be looking at somewhere between 25 to 50 years.
Benefits Of A Membrane Roof
- Lightweight
- Versatile
- High resistance to UV rays
- Superior resistance to extreme heat and fire
- Durability
- Easy to maintain
- Flexibility in varying temperatures
Disadvantages Of Membrane Roofing
- Prone to water ponding
- Punctures
- Shrinkage
How Much Does A Membrane Roof Cost?
Why the cost will vary depending on the type of membrane used, you can expect to pay $100+ per square metre.
5. Asphalt Shingle Roofs
While asphalt tiles are a popular choice the world over, they are not as commonly seen here in New Zealand. Asphalt shingles originated in America and gained popularity due to their fire-resistant qualities and advances in installation methods.
How Are They Made?
Asphalt Shingles have been available in New Zealand for over 40 years and are imported from other countries, namely the USA. Since the 1960s, manufacturers have traditionally used fibreglass as the base to manufacturing Asphalt shingles bonded together with urea-formaldehyde resin, however, they can also be made with a base of waste paper, cellulose and/or wood fibres. The exposed surface of the shingle is covered with crumbled slate, schist, quartz, brick, stone, or ceramic granules to provide different aesthetics and qualities, while the underside is usually coated with sand, talc, or mica in order to prevent them from sticking together.
How Long Do Asphalt Tiles Last?
Under average circumstances, asphalt shingle roofs have a lifespan of between 30 to 50 years.
Benefits Of Asphalt Shingle Roofs
- Versatile roofing option with a variety of finishes and colours
- Durable
- UV Resistant
- Suitable for use next to the ocean
- Some sound protection
- Relatively easy to install and repair
- Low maintenance
Disadvantages Of Asphalt Shingles
- Can become brittle over time
- Blistering
- Warping
- Cracking
- Eventual degradation
How Much Do Asphalt Roof Shingles Cost?
Expect to pay around $100 per square metre for asphalt shingles.
**Please note: All information and costs provided in this article are given as a guide only and are subject to change. Contact your local roofing professional for more accurate costings specific to your situation.
If you would like to discuss the costs of reroofing your home further, get in touch with Action Reroofing – the roofing specialists in Christchurch. Or you might be interested in finding out more about how to check if your roof needs replacing.
