Choosing from ColorBond or Zincalume is only the first part of the decision you need to make when considering a new roof.
Your roof serves many purposes and the main one is to protect your house from the elements, but as well as providing a waterproof cover to your home:
- The roof adds strength by uniting the design and making the walls solid and resilient.
- The pitch of the roof affects the ceiling space and this of course impacts on room temperature because your ceiling space acts like an insulator between your living space and outside. Pitch also affects the way water is dispersed and how likely it is that air-borne particles, such as sea spray, will settle on your roof.
An additional feature of the roof that is sometimes forgotten is that the roof design enhances the character and beauty of the home. The roof can follow the contours of the land, helping your house blend into the landscape or it can make your home stand out from others in the street by reflecting colour and style. The more of the roof you see, the more important it is for kerb-side appeal, which in turn has a major effect on potential re-sale value.
Most metal roofing is quite straight-forward, with long straight sheets of metal being used. However there are many other things, such as curved or translucent sheets that can be added to a roof line. To find out more about these things look at the specialised roofing page, or continue reading to find out more about basic roofing concepts.
Even in long, straight lengths of roof sheeting, there are lots of variations in the type of metal you can use, the sheet profiles and of course the colour scheme.
Different types of Metal
In Brisbane, today the type of metal most commonly used on houses is steel that has either been coated with very durable paint (Colorbond), or a zinc and aluminium alloy (Zincalume). Steel is the preferred metal for roofing today because it is strong, hard-wearing, flexible, lightweight and resistant to hail damage. It is also completely recyclable, which reduces landfill needs and our need to find more natural resources
The coatings make the steel resistant to corrosion, but they are still affected by sea spray and lead and copper. Zincalume and Colorbond should never come in contact with lead or copper, or water that has run off these metals. For example, hot water cylinder over-flow pipes are usually made from copper and so water from these pipes should not be allowed to flow onto your Zincalume or Colorbond roof.
Galvanised iron was used widely before steel became more common, and it is still available if you want to restore a period home, for example. If you are thinking of using galvanised iron, then we recommend the heavy version as it is far more durable than the light-weight one. This is recommended by manufacturers - Fielders.
Aluminium is another possible metal for roofing your home in. The biggest advantage to aluminium is that it is extremely resistant to pollution, so if your home is right on the beach or in an industrial area, the marine-grade aluminium could be the right material for you.
Copper ages beautifully, creating that unique greenish tinge, and it can last for centuries. Expense is probably the main reason why more people don't use it.
Because metal is so pliable, it can be rolled into different shapes that are called profiles and there are two basic profiles that metal roofing comes in: corrugated or squared. The corrugated profile is the most popular and while it has different brand names (e.g. Custom Orb or S-Rib Corrugated); the depth and width of the corrugations are still the same.
The squared profiles however vary in rib height and span width ( e.g. Spandeck, Trimdeck and Cliplock). These variations are used in different situations.
Deciding which profile is best for your home can be complicated as it could be determined by any of the following factors:
- How much roof line is visible from the road
- The age and style of your house, and whether you want it to look the way that suits the design
- The roof pitch
- Spacing of your existing battens or purlins
- Cost factor
- Personal preference for a particular profile
Because this is not a straight forward decision, it might be best discussed with your roofing contractor, but things that you could consider are:
- It was very uncommon to use anything by a corrugated profile until the 1960s, so if your house was built before this time, and you would like to keep the traditional look, then this would be your best option..
- If your roof has a high pitch then either corrugated or squared profiles would be equally good because water runs off them both easily. However, for flatter roofs (pitch less than 5 degrees) squared profiles are the sensible option as they have higher ribs than corrugated that deal better with slower flowing water. As a rule of thumb, remember that the lower the pitch, the higher the rib needs to be.
- Profile works closely with the gauge of the metal and the distance between battens or purlins. The bigger the spacing between your battens, the thicker the gauge of sheeting needs to be. For instance, domestic gauge (0.42BMT) corrugated metal roofing needs to be placed on battens that are no more than 1.1 metres apart, but 0.48BMT can be placed on battens that are up to 1.6 metres apart. Squared metal roofing sheets however, can cope better with wider-spaced battens.
If you are prepared to paint your roof, then you can have it any colour that you like, but if you want to save yourself some work you can choose from one of the many pre-painted Colorbond colours, or opt for the classic silver of plain metal.
The manufacturers of Colorbond pride themselves on making colours that complement the Australian landscape or suit both traditional and contemporary housing styles. The paint is baked on and so very durable. Of course some colours are likely to fade more than others, which may influence your choice.
Roof fixings include things like battens, screws and sealants that complete your roof.
Battens or Purlins
Strong winds blow roofs off houses every year in Brisbane, and so it is important to remember that a roof is only as strong as the framing it is sitting on. This means that getting the battens/purlins or rafters right is vitally important.
If your old roof has not been leaking and you don't have a problem with white ants, then it is most likely that you can use your existing framework. However, when some of the timber has rotted, or you wish to change the line of your roof in some way, the question we are frequently asked is "Am I better to use metal or wood?"
To Stark Roofing contractors, it makes little difference as we are skilled in both types of materials, but considerations are:
- Cost – metal and timber framing is roughly the same price, with metal being slightly more expensive, so if you have a large roof this might be a factor you would think about.
- Durability – correctly installed timber has stood the test of time, but it does not cope well with moisture. Metal battens have only been used for the past 40-odd years and there is no reported problem with them if they are fitted correctly and kept away from moisture or certain metals.
Self-drilling screws hold the metal roofing to the battens more strongly than nails and so they are always used by Stark Roofing to fix the roof to the framework. The type and number of screws used to hold a roof down depends on a mixture of manufacturing and civic regulations and common sense. For instance Australia Standard AS 3566 determines the type of screw that is to be used in roofing and if you live in Brisbane, building regulations state that a minimum of type 17 screw is to be used for installing a metal roof, where as in cyclone-prone Innisfail, the same sized screw can be used, but a special bracket is also required.
How many screws required for each roof is also stipulated by the likelihood of cyclones or not. At the time of writing this web site, regulations currently state that all roofs installed in Brisbane must be fixed in accordance to Australian Standard AS 3566.
If you can see the white caps of waves then it is strongly recommended that you use stainless steel screws to resist salt erosion.
Pop rivets are used to fix metal downpipes together and also some flashings to the roof. Pop rivets are extremely durable and virtually invisible from the ground.
Special silicones have been developed for metal roofing. They are UV and weather resistant, have a neutral pH, and will not shrink once they have dried. They come in clear as well as a variety of colours to suit most Colorbond colour schemes.
Unless the owner has pre-arranged a time for a quote, we always telephone to book a time with you and we endeavour to keep this appointment so that you are not inconvenienced. Because this is not the case with some contractors, we are sometimes asked if it is possible to provide a quote on roofing repairs or replacement without the house being sighted. As a general rule, the short answer to this is "No." This is because while it is possible to calculate the square meterage of house size off Google Maps if the house has four long walls, this is less accurate when there are many corners.
Other factors to be considered when we provide you with a quote are the
- Height of your house
- Condition of the roofing frame
- Number of and location of trees
- Access to your property for material delivery
- Any solar hot water panels, sky lights, whirly birds etc.
How close will the final price be to my original quote?
Normally the amount of the quote will be the same as the final price unless there is a structural or electrical problem that cannot be detected until the roof is lifted up. For instance if the rafters in the roof frame are damaged, a builder who is licenced to undertake structural work is required,a nd that company will charge you accordingly. Similarly if you need to hire an electrician to correct illegal wiring, that company will also need to be paid.
The Planning Stark Roofing does to replace or repair your metal roof
In order to commence work on any job, we must determine:
- If handrails or scaffolding is required
- Where new sheeting can be dropped off and stored prior to commencing work on roof
- Where power can be obtained safely for the power tools used by roofers
- If there is access to a toilet – people are on-site for hours at a time, and so it is necessary to have access to a toilet and hand basin
- Where sheeting can be safely lowered and stored on the ground to be collected when the job has been finished
If you are having a fibro roof removed then extra planning must be done. This includes:
- Masks and protective clothing are available for workers
- Removal and storage of fibro sheets prior to removal by an authorized person
Site Specific Safety Plan
As well as ordinary planning for the removal and replacement of a roof, safety planning is a big feature of the Stark Roofing work model. These factors are considered when developing a safety plan:
- Where overhead electrical wires are
- The best place to raise and lower sheets of iron
- Metal sheets are frequently thrown off a roof before they are stored on the ground to be collected when the job has been finished. It must be determined where this can happen so that people, pets and property are kept safe.
- If the old roof has been painted this can often be slippery because moss will grow on the painted surface.
- Pollution will also make the roof surface slippery, making it difficult at times to walk on the roof, particularly if it is damp.
- Sheets may slip and fall
- Best way to collect old nails or screws, but please note that some of these will be missed as they can bounce into the ground. This means that you need to be careful when mowing the lawn for the next few times.
Once the quote has been accepted, you will be advised of the following points:
- If scaffolding or ladders will be used in the installation of your new roof, or your roof repair.
- How many people are likely to be involved with the installation of the roof?
- How long it is likely to take to replace or repair the roof?
- Proposed start date.
- How long the work is likely to take?
- Roofing is noisy, so should you stay at home?
- Battens – sometimes we take off a roof and find rotten timber
- What if we find snakes, possums, or other wild-life in your ceiling?
- A safety plan that is designed to provide protection for the people who live in the house and their pets.
- No payment is required until the work is completed.
- Labour warranties are provided on all new or replacement work.
- All materials used by Stark Roofing carry a manufacturer's warranty