What does “Built Up Roof” Mean?
Definition of Built Up Roof in Construction
A built up roof is exactly that. This roofing technique is based upon the building up of several layers of roofing membranes, tar paper, or other designed types of membrane material. The layers are installed in a sequence to ensure that all the layers have been adhered to the layer on the bottom. The built up roof technique is used for any roof that cannot be shingled because the pitch is too low. The building code identifies the lowest pitched roof where shingles are allowed. Built up roofing is basically a flat roofing technique, and was the most popular form of roofing for flat roofs, until the single ply roofing technique was developed and became popular. Built up roofing systems normally require a tar kettle or vessel that large solid pieces of asphalt tar are heated to their melting temperature. This heated liquid is pumped to the roof elevation and used to adhere the ply’s of roofing membrane together. Safety is an issue with the use of a built up roof application due to the fire hazards of the asphalt tar kettle. Fire suppression measures are extremely important with a built up roof installation. Hot torches are used on the roof surface to maintain the heat in the asphalt material and open flames are a part of the installation. The use of the built up system of roofing is rapidly being replace with single ply roofing systems that eliminate the fire hazards and the time required for the proper installation of the built up roof.