Built-up roof systems have been around in some form or another for almost 200 years. Known as the most traditional roof system, it has a typical life expectancy of 20-40 years. The multiple layer redundancy and tough surfacing make the Built-up roof the most resilient system available.
Along with its reputation comes the price tag. Typically, a complete
tear-off with a Built-up roof system installation is the most expensive
option available to a building owner. While all roof systems are good
roofs if installed properly, the Built-up roof is known as the best, and
should last the longest.