Built up roofing (BUR), which is also known as “Tar & Gravel Roofing” is a durable commercial roof construction option that we can install. These systems usually consist of light-colored material that assists in reflecting ultraviolet rays. While built-up roofing is incredibly durable and long-lasting, it still needs to be properly maintained and, occasionally, repaired. You can expect a well-maintained roof to last 20 to 30 years. On average, however, a roof’s life expectancy begins to fall at 20 years. This will certainly happen if your roof has not been professionally installed and maintained. This material often is one of the most affordable in the roofing business.