Ballast refers to a layer of heavy material, such as gravel or stones, that is used to weigh down a roofing system and hold it in place. Ballast is typically used in commercial roofing systems that are designed to be installed over a flat or low-sloping roof deck.
The ballast layer is typically applied over a roofing membrane, which serves as the primary waterproofing layer of the roofing system. The ballast helps to protect the roofing membrane from damage due to exposure to UV radiation, temperature changes, and foot traffic. It can also help to improve the energy efficiency of the building by reflecting solar radiation away from the roof surface and reducing the amount of heat that is absorbed by the building.
The type and amount of ballast used in a roofing system will depend on a variety of factors, including the design of the roofing system, the location of the building, and the local building codes and standards. Ballast may be applied using a variety of methods, including loose laid, mechanically attached, or adhered to the roofing membrane.
It is important to ensure that the ballast is properly installed and maintained to ensure the longevity and performance of the roofing system. Proper ballast installation can help to reduce the risk of damage to the roofing membrane and ensure that the roofing system meets all applicable building codes and standards.