Tar and gravel roofs are the most popular type of material used on large commercial buildings. It is installed by layering fiber-glass sheeting and hot bitumen, commonly known as tar, on top of each other. The final layer is then topped off with stone, rock or gravel. This type of roof is popular for a reason and has a lot of advantages. However, before you decide on a tar and gravel roof it is important to know its limitations.
Tar and gravel are only recommended for roofs that are flat or slightly sloped. This is because the top layer of gravel protects the sheeting underneath. In order to preserve the integrity of the roofing material, gravel should be inspected annually for thin or bare spots. Wind, rain and foot traffic will move around and diminish the gravel, causing damage to the roof. If technicians need to install equipment, like HVAC units or solar panels, then roof gravel vacuuming is the easiest way to clear space for work to be done. These types of roofs are not meant to be walked on regularly.
One of the main reasons tar and gravel roofs are popular is because of the modest price. Keep in mind that these roofs typically last between 10 to 20 years. As with most building materials, the cheaper the material the shorter it lasts. If the gravel is checked and replenished regularly and the building doesn’t face extreme weather, then the roof life may be extended to 30 years.
Tar and gravel roofs offer excellent protection against heat and fire. Instead of UV rays roasting a solid surface, heat and light are scattered throughout the textured gravel. This can keep the building cooler in the summer. These roofs have a class A fire rating. This is the highest degree of fire protection, required for high-risk buildings such as schools and churches.