BUR or Built-up Roofing has been used in the U.S. for over a century. Most people call it by another name–-tar and gravel roofing. Unlike the single-ply roofing that is extremely popular today, this form of roofing involves alternating layers of bitumen and fabrics that knit together to create a “membrane.” It is then finished with an aggregate layer or coating.
BUR often starts with a rigid insulation layer, then there are felts, fabrics, or mats that are saturated with bitumen. The most commonly used bitumen on these types of roofs are asphalt (which works as a better fire retardant than the others), cold-applied adhesive, or coal tar. If you’ve ever watched roofers spreading a gooey black substance on a roof with a mop or mechanical spreader, you’ve probably been watching them create a built-up roof.
The finish of a built-up roof sometimes looks like a rocky beach because gravel, mineral granules, or slag are mixed in with the asphalt but these roofs can also be smooth. BUR is primarily used on low-slope and flat roofs, mainly older industrial buildings and schools.
Built-up roofing systems have many variables such as the types of mats that reinforce the ply sheets and the type of bitumen used. These materials affect the cost of the project but the decision of what types of varieties are not all decided by budget. Hot asphalt, for instance, can be quite noxious and does not make a good solution for environmentally-sensitive projects.
What Can You Expect with Built-Up Roofing?
- Good waterproofing
- High maintenance
- High-life cost maintenance
- Ultraviolet protection
- Labor-intensive installation
- Fumes and vapors during installation
- Lower materials cost but higher labor costs
BUR and other types of roofing require a professional assessment to decide what is the best fit for your project. There are many factors that go into the decision of whether you should use a single-ply roof solution or a built-up one.
At Anderson Contractors, we have extensive expertise in all types of roofing. We can help you find the roof that fits your investment’s needs and your budget. Call us today to find out what roof will work best for you.