Metal roofs like those commonly used in commercial buildings are becoming more popular in residential home construction because they are easier to maintain and have a longer lifespan. However, individuals who have homes with metal roofing may wonder whether tar, a common material used in traditional shingle roofs, can be used on metal roofs as well.
Reasons for Tarring Metal
People may wonder whether they can tar a metal roof to apply shingles in order to combine the durability of a metal roof with the appearance of a traditional roof. Alternately, some may wonder if tar can be used to fix problems on a metal roof, such as small gaps where metal sheets meet.
Tar can actually be used on a metal roof, and many people slop the black goop onto valleys, roof-to-wall joints and plumbing vents to prevent or stop leaks, notes William Kibbel III, a home inspector and restoration consultant who serves as vice president of the Tri-County Inspection Co. in New Jersey, in an Old House Web article. For shingle application, using tar doesn't make sense because modern metal roofs are factory-made to look like traditional, shingled roofs, according to the Metal Roofing Alliance.
"Roofing tar is an unsightly and temporary fix for a problem that should be repaired properly and permanently," said Kibbel in the Old House Web article. Other materials like paint can be applied to provide a better, more attractive result.
Acrylic primers and paints can be used on metal roofs, Kibbel noted. However, for maximum durability, he recommends using an elastomeric coating. Typically, metal roofs need to be painted every two to four years, but these types of coatings can last as long as 10 years.
Benefits of Metal Roofing
Originally, metal roofs appeared at the end of the 18th century in the United States. Early metal roofs were typically made of weaker metals and often leaked and rusted easily. The metal roofs of today are two to three times more durable than a regular roof, according to the Metal Roofing Alliance. That means that a metal roof installed on your home today may still be around and in good shape 50 years or more from now. Metal roofs are also safer, because they can generally withstand wind gusts of up to 140 miles per hour. Additionally, consumers can purchase metal roofs that look just like traditional roofing materials, including asphalt shingle, cedar shake, clay tile or slate, notes the MRA Web site. This means that you don't need tar to finish a metal roof.