Cement tiles vs Terracotta

I am in need of replacing my roof tiles. I have heard that cement tiles have the problem of cracking over time as opposed to terracotta which meant to last . Can anyone verify this? Alternatively I am thinking of jut using corrugated iron as the cheaper alternative. Any advice will help.

i have personal experience between the two.

1992 Hailstorms in Sydney, every house in the street lost all their roof. Ours didnt, They were all clay tiles, ours was concrete.


I will be replacing the roof on an 1950 L shape weatherboard in inner west Melbourne shortly.
It has cement tiles and their life expectancy of 40/50 years has reached its use by date.
Cement tiles do become brittle with age but should not be as heavy as terracotta or similar.
I will be using CGI because it fits in well with the streetscape , it is light weight compared to tiles and it is fairly easy to install if you are handy.
Some areas might insist that a licenced plumber installs a gal roof and some councils might insist on a coloured gal to avoid sun glare.
Guess it would depend on what looks best in your area but looking right around Oz original gal and colourbond are very trendy products.
Seeing that colorbond/gal roofing has been thrown into the discussion, I think it is fair to say each has their advantages and drawbacks:

Terracotta tiles are baked clay and has the potential to last roughly forever. They are lighter than concrete but, as Rolf points out, not as strong (or perhaps a better term is "more brittle"). Available glazed or unglazed, although I think I read that unglazed terracotta tiles can be almost as heavy as concrete because they absorb some amount of water.

Concrete tiles are cheaper, have a limited lifetime (although still pretty good), and are heavier.

Colorbond is lightweight, cost-effective (but I don't think "cheap") but it is noisy in heavy downpours and provides little ventilation to the roof space. I don't think you can reasonably expect the longevity of colorbond to match either terracotta or concrete tiles. Certain substances cannot be used in conjunction with colobond, for they cause the colorbond to corrode. My memory can't recall what they are, but I have read somewhere that even rainwater runoff from an incompatible surface could be problematic. Don't know how leaves and their tannins might affect colorbond, but it could be a consideration.

In a fire-prone area colorbond might be a better choice because it is a sealed roof (except under the roof edge) thereby reducing the chance of embers entering the roof.

Some people might consider terracotta roof tiles a more "upmarket" product (in cost, they are) over concrete tiles if you choose to resell your property later.

Fortunately your house previously had concrete tiles (the heaviest) so it is now capable of holding any style of roof.

I don't think you will be disappointed with either choice, so long as you choose a good brand etc. Aesthetics will also play a consideration - there is usually a wider range of profiles available in concrete tiles - I'm not sure how the color ranges compare).
Originally posted by Kevmeister
Certain substances cannot be used in conjunction with colobond, for they cause the colorbond to corrode. My memory can't recall what they are

Lead and copper.
Lead flashings are typically used on tile roofs, they use colorbond or soft zinc on colorbond & zincalume roofs.
Copper from water pipes also causes corrosion. The shepards crook on low pressure hot water systems can cause problems if the overflow is allowed to drip onto the metal roof. The overflow water contains minute amounts of copper which reacts with the zincalume coating.

There are a few points to remember about cement and terracotta.
Cement will fade over time. the colour is applied as a cement slurry over "wet" cement as the tile is formed then dried. Cement tiles actually develop strength over time and have a design life of 50 years.
Cracking is not an issue with either tile. If tiles crack then it is either a manufacturing defect or the result of sloppy tiling. In the case of cement it is caused by batching stuffups and in terracotta it is commonly caused by poor extrusion or kiln firing problems.
Good terracotta tiles make a "clink" sound when tapped. Dodgy ones sound "Drummy" or hollow when tapped.
Terracotta can prematurely fret when exposed to high salt levels but again it really depends these days on type of clay used and how well it was fired. If you are thinking of using it with coastal exposure check with the manufacturer.
Terracotta comes with a lifetime warranty (50Yrs) or at least it did when I worked in the industry.
Water absorbtion for terracotta is 10% regardless of glaze. The glaze on a tile is not to waterproof it but purely as decoration. Terracotta is fired at 1020-1060 degrees C.
Manufacturing costs for terracotta these days is only about 15% more than cement but in the early nineties it was 100% higher. They just havent removed the markup.
On an average home 30% of what you see is the roof. A glazed terracotta roof will look the same for decades.
Paul and Dee
Life of building materials

Thanks for useful information on this page.
Can some one please provide me different sources for the information about minimum, maximum and average life of commonly used residential building material (including terracotta and concrete roof tiles, steel roof). I have a fairly good idea about the expected lives of these materials, however I have to find references to make it more authentic. It is required for my post graduate research. Any advice will help.
Be careful when removing a tile roof cover and replacing with colorbond or zincalume lightweight steel sheet. Consideration has to be given to the wind rating (N1, N2, N3 etc) for the site, and appropriate hold down provisions installed for the lighter weight roof. Example - N2 rated site requires (for a tin roof) tie downs at 1200mm centres to the perimeter of the roof frame, and internal specific tie downs as well. Tile roof in N2 rated site does not require any tie downs.
So you could be blissfully unaware that your newly finished tin roof, replacing a tile roof, could blow off in the next severe storm!!
Food for thought eh?