New Hamptons style house with new roofing and guttering

How To Calculate The Cost Of A New Roof

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Measure the area of the roofing you need to replace. If you have access to the roof of your home, you can use a tape measure to check the length and width of the sections that need to be replaced. Multiply these together to get the square meterage of the roof.

If you don’t have access to the roof, you can estimate the area based on the size of your home using trigonometry. To calculate the roof area, divide the size of the house by the cosine of the roof pitch:

House Area ÷ cos(Roof Pitch) = Roof Area

100m2 ÷ cos(22.5°) = 108.22m2

For reference, most homes in Queensland use a roof pitch of 15° or 22.5° degrees. So, in this case, a house with a 100m2 floor area would have a roof area of approximately 108m2.

Cost Calculation

Once you know the area of roofing you need to replace, you can calculate the total cost. We typically find that it costs $80 to $120 per square metre to replace a roof. If we continue our example from above, we can see that:

108m2 x $80 = $8,640

This rough estimate includes removal and disposal of the existing roof materials, as well as replacement with Colorbond sheeting (including building blanket, battens, sarking and other materials as necessary).

The actual cost of replacing your roof varies widely depending on the materials you choose, the design of the roof, access to the site and much more. Most roofs fall within the above range, but there will always be exceptions.


Finally, it’s time to seek an accurate quote.

If you are serious about a replacement roof, you will need a firm quote tailored to your specific requirements. We recommend contacting Gutter and Roof Repairs to obtain an accurate, no-obligation quote. We’re happy to visit your home, measure your roof and assess your needs. That will allow us to put together a firm estimate for the work that’s involved.

Simply call Gutter and Roof Repairs on 0421 460 580 or send us an email to book an inspection.

Ready to Find Out More?

Our qualified roofers are experienced with repairing and replacing all types of gutters and roofing. Fill out the form to book a quote, or contact us using the Request a Quote form. 

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Gutter and Roof Repairs is based in the heart of Brisbane, and our services are available all over South East Queensland.

Brisbane • Ipswich • Redlands • Logan • Caboolture

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