Life Expectancy of Roofing Materials
(And Selected Roof Systems)
(The table is at the end.)
How Long Does a Roof Last?
The following table provides typical expected useful service life durations for various roofing materials and roof systems. The values for the expected lifespans are based on recent developments in roofing materials technology. The table covers current roofing products, so in some cases the expected service life we give will be significantly longer than what can be expected from older products in existing roofs which were installed years ago.
There are many factors that go into predicting the length of the useful service life of a roof. The quality and reliability of the manufacturer is very important. The local environment that the roof will have to endure is also a big piece of it. Roofing materials in coastal regions, with high levels of corrosive environmental salt, tend to deteriorate faster, for instance. Many roof types don’t perform well in deserts, with the continual barrage of UV rays. (Asphalt and EPDM should both be expected to last on the low end of the predicted range in a place like El Paso, Texas. Asphalt in general and EPDM flashing material are both highly vulnerable to sunlight.)
The use of proper fasteners and other accessories is crucial to long-term roof performance. An all-too-common reason for the premature failure of tile roofs, for instance, is the use of low-quality fasteners and battens, which fail long before the tiles themselves would have.
All other things being equal, though, it’s the thickness of the material that most affects the expected lifespan of a roof. As a rule of thumb, the thicker the shingle, the panel, the membrane, or the tile, the longer the roof will last.
The warranty periods given in the table are for typical manufacturer’s material warranties. A material warranty only covers the performance of the roofing material itself (basically, it just covers factory defects, which are very rare these days). The initial workmanship of the installation and the performance of other parts of the roof assembly, including the roof deck and any other components not produced by that manufacturer, will not be covered by the manufacturer’s warranty. Those things will be covered by the roofing contractor’s workmanship guarantee if they are covered at all. Contractor’s workmanship guarantees last for a much shorter period of time, usually 1 - 5 years.
Many manufacturers have recently changed their warranties to “limited lifetime” warranties, especially for high-end asphalt shingles. If you read the fine print, however, you’ll see that the coverage becomes “prorated” after 20 - 25 years. This means that the manufacturer starts to guarantee less than the full replacement value of the roofing material after that point.