NEW METAL ROOFS – FAQ

COLORBOND® steel combines the corrosion resistance of a ZINCALUME® steel base with a durable, oven baked paint finish. Find out more on How It Is Made.

For COLORBOND® steel and ZINCALUME® steel, BlueScope Steel offers a warranty against corrosion to perforation by weathering in the natural elements for a period of up to 36 years* from the date of installation. BlueScope Steel also warrants that the paint system on COLORBOND® steel will not flake or peel due to natural weathering for a period of up to 20 years* from the date of installation.
The 36 year* COLORBOND® steel and ZINCALUME® steel for Roofing Warranty only applies providing all of the following conditions are met:
– Installed pitch of the roof is equal to or greater than 5 degrees above the horizontal.
– The roof is fully lined and does not contain exposed eaves or other areas sheltered or unwashed by natural rainfall.
– The roof is located more than 5km from salt water.
– All fasteners used for fixing the product to be in accordance with BlueScope Steel recommendations and comply with Australian Standard AS3566: Class 4 where applicable.
* Warranty terms and conditions apply. Warranties are not available for all products and applications. The duration and terms and conditions of available warranties vary according to product use and application.

All coloured materials will change colour when exposed to UV light – the paint finish on your car, the clothes on your line, and so on. When it comes to steel building materials, the extent of colour change is influenced by factors such as the colour itself, the aspect, the design of the structure and the environment. Dark colours are inherently prone to more noticeable colour change than lighter colours. Individual perceptions also come into play. How you see colour can differ greatly to someone else.

Using thermally efficient roofing materials like COLORBOND® steel can help reduce your cooling and heating costs. In summer, a lightweight insulated roof made from COLORBOND® steel can assist in minimising the amount of heat radiated into your home at night. That’s because COLORBOND® steel has a low thermal mass, so it cools down fast once the sun is off it.
In winter the same steel roof, properly insulated, helps keep the heat inside. Building Regulations for your area will prescribe the level of insulation you will require. The choice of colour can also influence thermal performance. Lighter colours, in particular, radiate less heat during summer. Building regulations may allow you to install less insulation if you use lighter colours in warm climates.

Generally, a metal roof will stand up well to hail storms. The roof sheeting will absorb the energy of the hailstone and remain structurally sound. However, indentations may occur along with loss of the paint topcoat.
In most cases indentations from hailstones do not affect the life of a COLORBOND® steel roof. The only causes of concern will arise from: – Low pitch roofs with significant hail indentations in the pans. This can lead to ponding and dirt accumulation, which may promote corrosion.
– Low pitch roofs where sheet overlaps have been significantly deformed. The anti-capillary effect can be lost and water could be drawn into the sheet lap, resulting in corrosion.
In the event of ponding due to indentations or damage to sheet overlaps, the affected sheets should be replaced as soon as practicable to maintain the life of the roof. Loss of the paint topcoat arising from impact of hail stones will be an aesthetic issue only and will have no appreciable effect on the corrosion performance of the COLORBOND® steel roof.

Temperature variations can cause pierce fixed metal roof sheeting to expand and contract, sometimes resulting in roof noise. This is more likely during rapid changes in the temperature caused by such things as heat from the morning sun, afternoon cooling, passing clouds or gusts of wind. What’s the technical explanation? When movement is suppressed the stress in the sheet builds up and may exceed the frictional restraint. Energy is then released as noise associated with sheet movement. The level of noise depends on the frictional restraint. For most roofs there may be some minor creaking. However, when there is excessive thermal movement and poor installation practice, frictional forces can build up to create loud, sharp cracking noises. Although noise problems are rare, they are usually associated with dark coloured roofs fastened directly to timber. This is due to the friction characteristics of the steel-timber interface (increased noise if the timber is wet) and the fact that darker coloured sheeting is subject to greater expansion.
It’s been found that the risk of this type of noise can be reduced by:
– Using an insulation blanket with sarking between the sheeting and timber supports (this also provides heat insulation, a vapour barrier and reduces rain noise).
– Using steel battens to support the sheeting.
– Using a reflective foil laminate between the sheeting and timber supports (this also provides heat insulation and a vapour barrier).

No. In summer a lightweight roof made from COLORBOND® steel or ZINCALUME® steel causes less heat to be radiated into your home because it cools down faster at night. And in winter, the same steel roof, properly insulated, helps keep the heat inside. This can result in reduced cooling and heating costs.

Many people enjoy the sound of rain falling on their steel roof. They feel more attuned to nature, or it brings back fond memories of childhood. For those who don’t, rain noise can be reduced by using an insulating blanket. This is placed directly under the roof sheeting to dampen sound vibrations, reducing noise and making for a peaceful environment inside.

Some manufacturers do sell roof sheeting made from COLORBOND® steel with a top coat on both sides. However, colours and styles may be limited and you should confirm availability with your supplier.

COLORBOND® steel and ZINCALUME® steel are thermally efficient roofing materials, radiating less heat into your home as they cool down faster at night. Lighter coloured roofs, irrespective of material, reflect more heat than darker shades. The result of this being less heat available to be radiated into your home. To reduce the transmission of heat into a building, insulation can be easily incorporated during the installation of the steel roof sheeting.
There are two types of insulation commonly used during the installation of steel roof sheeting. They are:
– Reflective foil, commonly referred to as ‘sarking’:
Reflective foil laminates which are commonly used to provide heat insulation under roof sheeting can serve a dual function as a vapour barrier, simply by thoroughly sealing the foil overlaps with moisture impervious adhesive tapes. The laps should be about 100mm and kept in close contact when positioning the laminate so the tape can be readily applied. The laminate must be allowed to drape between the roof supports so the cold temperature of the roof sheeting will not be transmitted to the laminate by contact. If this were to happen condensation could form on the underside of the laminate and may drip into the ceiling space.
– Combined foil and glass/wool insulation blanket:
This blanket should be installed over the battens with the glass/wool insulation facing up in temperate zones and facing down in tropical zones. For advice appropriate to your area, please phone BlueScope Steel Direct on 1800 022 999. There should be no sagging between battens to avoid air spaces between the fibreglass and the underside of the roof sheeting.
This information is intended as a guide only.