Single ply roof guarantees usually cover 15-20 years, but in reality, these...

https://www.4shared.com/office/Q9ZZDzKPge/pdf-27402-44163.html

Single ply roof guarantees usually cover 15-20 years, but in reality, these roofs can last 25-40 years if looked after properly. Guarantees focus on materials and installation, not daily wear and tear