The life expectancy of roof tiles made from concrete should be a minimum of 60 years. The underlay will have a shorter lifespan which typically lasts for a 40 year period. Of course, this is based on average conditions. There are a number of factors that could contribute to the lifespan of concrete roof tiles.
Some of these factors are:
1. Color of roof – A dark roof absorbs more heat, which shortens the lifespan.
2. Angle of roof slope – Higher pitch roofs tend to last longer.
3. Orientation of roof surface – A roof slope facing north will get more sunlight, and have a shorter life.
4. Walking on the roof – Concrete roof tile is easily cracked if not walked on carefully by a professional familiar with this type of roof. But tile is more resistant to hail damage than other types of roof coverings and, because of its weight, less likely to be blown off in a storm.
5. Harsh climate – Severe weather, both harsh winters and hot summers, along with big temperature swings within a 24-hour period, also shorten lifespan because of the expansion and contraction of the concrete tiles. Also, if installed too tightly, the tiles will crack prematurely from the temperature changes.
If you are considering switching to concrete tile from a shingle roof, be aware that the additional weight of the tile (averaging 50 kgs per square meter, which translates to a 1/2 ton for a 3 x 3m area of roof surface) means the roof structure must be sturdy enough to support the weight. Your local building department may require that the roof trusses/rafters be certified as adequate by a licensed structural engineer or the roof be reinforced to carry the additional load—unless you can prove that the home formerly had a tile roof years ago.