A slate roof will easily last over 100 years which is at least double of what other roofing materials can offer.
Slate roof lifetime.
While man made slates are typically cheaper and easier to install they only tend to last for around 20 years.
This can vary depending on the manufacturer.
Durability and low maintenance.
The biggest downside to slate tile roofs.
Many slate tile manufacturers offer up to 100 year warranty on their products.
These life expectancies are general experience with the material and do not consider installation or environmental factors which vary from one building to the next.
For fibre cement roof slates the life expectancy is a little shorter at around 50 60 years.
Typical life for pennsylvania slate roofs is 40 50 years.