Not much is written on this subject in Australia, however the life of roofing materials is not only dependant on what the manufacturer of a roof covering material may guarantee. It is also highly dependant on the installer how long a roofing product’s life may be.
However, we will assume that the covering of your choice has been installed by a competent installer, so be vigilant in your choice when choosing an installer.
For this blog we will look at the most available mainstream products in Australia – concrete roof tiles, terracotta roof tiles and an array of metal roofing profiles with the main profile being corrugated colorbond.
Looking right at the most used roof covering in Australia – concrete roof tiles – when I started out as a roof tiler concrete roof tiles were given a 50 year guarantee against decay and lamination, although the colour lasts only up to about 10 years and that is being generous.
I have found that the decay and lamination claim to be true as I have been a roofer for over 50 years and long after the 50 years the concrete tiles are still performing and as roof painters may claim them to be porous, this is simply untrue for the most they are not porous. So concrete tiles are a good proposition with the only drawback they are extremely heavy at approximately 15 ton compared to metal roofing approximately 1½ ton and they need ongoing maintenance i.e. ridgecapping.
Terracotta tiles – I believe are a waste of money over concrete tiles, with the exception that they do keep their colour as the colour is baked into the product, so you will get a guarantee for the colour but little else. It is my experience that unglazed terracottas can become very brittle and highly glazed terracotta can laminate especially in areas that have heavy frosts, then by the sea salt action can laminate the water courses. If you believe the manufacturers of these products these problems have been addressed with the terracotta of today. However, I reserve my opinion on that one, only time will tell.
My recommendation – if you must have roof tiles go for concrete.
With both terracotta and concrete roof tiles, these will need ongoing maintenance to ridgecapping etc.
Then you have metal roofing – Trimdek, Kliplock etc and the most popular corrugated colorbond. The most popular is corrugated colorbond, this product and profile will give similar results to concrete roof tiles and provided it is installed properly will last just as long however enjoys the fact it is much lighter in weight so whilst being slightly higher in price it will cost much less in structural timber. If you were to ask me what I would suggest, it would be corrugated colorbond – provided it is installed properly. You may have to paint it every 20 years however in my opinion it enjoys the best life of the roofing materials mentioned. Stay away from low pitched roofs these are nothing but trouble, however if you must have a low pitched roof I would suggest a metal deck roof i.e. Kliplock etc.
So there you have it my suggestion a corrugated colorbond roof will give best results in the long run, whatever roof covering you choose don’t forget you will need an effective roof ventilation system to keep you cool in summer and the roof cavity dry from condensation problems, look on this site for the best roof ventilation systems for tile or corrugated colorbond roofing.