The Cost of Roofing for
your Renovation
Part One

Roofing is one of the most important elements in your home renovation or build. It is the first layer of protection against the elements. It also serves an important function in your home’s insulation system.

Article By: Style Plus | December 2015

01

The Cost of Roofing for your Renovation or New Build

Deciding on a new or replacement roof can be a formidable task considering the range of roofing options available to homeowners today. In this first article of the 'Cost of Roofing', the Style Plus team explores different roofing system options from clay tiles to metal roofing for your renovation or build:

• Concrete & Clay Tiles.
• Metal Roofing Systems.
• Pressed Metal Tiles.
• Longrun Metal Roofing.
• Minimum Roof Pitch Summary.

Monier Concrete Tiles | Style Plus

Concrete & clay tiles

Traditional tiles are available in concrete or terracotta clay tiles and come in a multitude of shapes, profiles and colours. The main difference between the two is that the colour of the tiles is inherent to the terracotta clay tiles are made from, whereas for concrete tiles a coloured glaze is applied and baked on, meaning it will fade over time.

The benefits of concrete or terracotta clay tiles are that they will not rust, warp or corrode - a problem with other roofing materials. They are effective at blocking noise from outside the building, including the noise of rain and hail. They don’t make the cracking noises associated with expansion and contraction. They cope well with wet weather, as the laps in the tiles allow moisture and dampness to dry out and escape. They are ideal for coastal locations that endure wind, spray and salt. And they are tank water safe i.e. the water that runs off a tiled roof is potable.

Both are easy to take care of, with required maintenance mainly consisting of cleaning the roof and removing lichen from time to time.

One disadvantage of concrete and terracotta clay tiles, is their weight. They are heavier than other alternative roofing systems. Therefore appropriate roofing support should be present in order for you to install this type of roofing system.

Costs for concrete & clay tiles are from $140 per meter square.

Metal Roofing Systems

The benefits of metal roofing systems are that they are light weight, energy efficient, durable, and can be made to resemble shingles and clay or metal tiles.

The vast majority of metal based products in New Zealand utilise the same ZINCALUME® coated steel. Effectively ZINCALUME® has replaced the traditional galvanised corrugated iron and offers many benefits.

The primary issue with metal roofing systems is ‘corrosion’. New Zealand has a high atmospheric salt content, which means corrosion occurs practically everywhere. Therefore, when selection a roofing system for your renovation or build, materials and finishes must be selected carefully for the conditions in that area.

Two of the most common types of metal roofing systems are:

• Pressed Metal Tiles.
• Longrun metal roofing.

Metal Roofing Systems | Metalcraft | Style Plus

Pressed Metal Tiles

Metal tiles, shingles and shake panels are press formed to provide a variety of shapes resembling clay tiles and wooden shingles or shakes. They are interlocked or overlapped together laterally and longitudinally and are clipped or fastened to timber or steel battens.

The metal used for the manufacture of metal tiles, shingles and shakes is typically G300 grade zinc/aluminium alloy-coated mild steel.

Pressed metal tiles made from steel invariably have an additional protective coating applied over the metallic coated steel. An alternative coating can be provided by applying crushed stone or ceramic granules to the base metallic coated steel and attached by an adhesive coating. In this case a clear acrylic coat is normally applied on top of the stone coating. These coatings give protection to the metallic coated steel base, as well as providing a decorative finish.

Pressed metal tiles are suitable for roof pitches from 12 degrees.

The cost is from $55 per meter square.

Pressed Metal Tiles | Gerard Roofs | Style Plus
Longrun Metal Roofing | Style Plus

Longrun Metal Roofing

Another lightweight roofing option is longrun. From the corrugated profiles that bring to mind the iconic kiwi bach, to classic standing seam profiles, the versatility of longrun steel roofing or cladding enables you to make a personal style statement when building or renovating your home.

Pre-painted steel copes well with the corrosive, salt-laden air of most of New Zealand and are suitable for almost every design, whether you choose sleek long straight lines, modern innovative draped curves or a villa with a traditional bullnose veranda. Steel can provide a delicate quality and lightness of a building within a landscape or a solid, strong rock like structure. It also blends or provides a contrast for concrete, wood, schist and many other building materials.

The cost is from $30–$75 per meter square.

Minimum Roof Pitch for Roof Systems.


Roofing Type
Profile | Style
Min Pitch
Conditions
E2|AS1 Compliant
(1) Membrane Roofing
  • EPDM Butyl Roof
  • Roofs
(2) Profiled Metal Roofing (max. length = 18 m)
  • Trapezoidal
  • Where crest height < 27 mm
(3) Profiled Metal Roofing (max. length = 18 m)
  • Trapezoidal
  • Where crest height > 27 mm
(4) Profiled Metal Roofing (max. length = 18 m)
  • Trough
(5) Profiled Metal Roofing (max. length = 18 m)
  • Custom Profiles (copper, zinc, aluminium, stainless steel)
  • Dependant on profile, length of trays and local conditions
(6) Shakes   Shingles (Timber)
(7) Shingles (Asphalt)
  • 15-18° min. recommended
(8) Pressed Metal Tiles¹
  • Standard
(9) Pressed Metal Tiles¹
  • Shake Style
(10) Pressed Metal Tiles¹
  • Concrete – Type I
  • With Underlay
(11) Pressed Metal Tiles¹
  • Without Underlay³
(12) Pressed Metal Tiles¹
  • Concrete – Type II
  • With Underlay
(13) Masonry Tiles² (to rafter length 4.5 m)
  • Concrete – type III
  • With Underlay
(14) Masonry Tiles² (to rafter length 4.5 m)
  • Terracota – type I
  • With Underlay
(15) Masonry Tiles² (to rafter length 4.5 m)
  • Terracota – Type I
  • Without Underlay³
(16) Masonry Tiles² (to rafter length 4.5 m)
  • Terracota – Type II
  • With Underlay
(17) Masonry Tiles² (to rafter length 4.5 m)
  • Terracota – Type III
  • With Underlay
(18) Slate
  • Natural/Man-Made

  • ¹ Pitch must be increased by 1° for each additional 0.5 m of rafter length over 12 m.
  • ² Pitch must be increased by 1° for each additional 0.5 m of rafter length over 4.5 m.
  • ³ Roof underlay is required for any roof receiving discharge from a spreader.
  • ✔ ✘  E2/AS1 Complient/None Complient.

Whilst all information is considered to be true and correct at the date of publication, changes in circumstances after the time of publication may impact on the accuracy of the information. The information may change without notice and Style Plus is not in any way liable for the accuracy of any information printed and stored or in any way interpreted and used by a user.

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