Denver Roofing: Article About Built Up Roofing
Low slope roofs are the standard for many types of commercial buildings. They provide ample protection from the elements as well as additional space for equipment in tightly packed commerce districts. Selecting the right type of roof covering for these buildings is important. These roofs must protect not only the structure beneath, but also the entirety of the business within. A leaky roof at home may damage some possessions and leave homeowners with repair bills, but the same problem in a business could destroy inventory, equipment or records. With the tight margins under which most small businesses operate, a leaky roof has the potential to cripple the whole operation. Denver roofing contractors know how important it is for commercial roofs to be durable and water tight.
Built up roofing is among the most popular options for low slope commercial installations. This type of roofing involves applying alternating layers of matting, also known as roofing felt or ply sheets, and adhesive to form a watertight barrier. The adhesive used is usually one of three types: bitumen, coal tar or cold applied sealant.
A roofing companies expert from All Around Roofing of Denver can answer any questions you have about insulation or siding.
Asphalt or coal tar must be heated and mopped onto each layer of ply sheet in order to help it adhere to the next sheet and the one below it. Once the hot sealant cools, it forms a hard surface and permanently bonds the ply sheets together into a single waterproof membrane. Cold applied sealants are solvent based and do not require heat to apply. They are more similar to glue and harden as they dry. An added benefit of cold applied sealants is the lack of harmful vapors, which are present during the application of hot mix.
The ply sheets are made from either glass fiber or organic matting and treated with asphalt to increase their water resistance. They typically come in 36 inch wide rolls that are overlapped across the roof to form each layer. Older installations began by applying the first layer directly to the decking, but newer roofs add a base layer of foam or composite boards to help with thermal and acoustic insulation prior to the first layer of roofing felt.
Built up roofing is finished with a layer of aggregate, which protects the ply sheets from abrasive damage. The aggregate can be anything from gravel to ceramic pellets. The choice really depends on the materials available locally and the budget. An added benefit of this finish is the ability to walk on the roof for maintenance needs as well as providing additional outdoor space.