DOT – Department of Transportation

What is the DOT – Department of Transportation ?

Definition of DOT – Department of Transportation in Construction
A drain that is installed within the roofing systems of a structure. Normally roof drains are required in flat or semi flat roofs and not in pitched roofs. Roof drains are usually cast iron, metal or a synthetic material that includes a grate to prevent solids, branches, debris to drain down the roofing drainage system. The roof drains are piped into the storm system of the project through either cast iron or pvc pipng dependent upon codes and design. There are several different types of roof drains, however they are always intended to be installed at the lowest portions of the roof and are usually coordinated with the tapered insulation systems installed within the flat roof systems. Roof drains are vitally important to the structural integrity of the roofing and roof decking structure. The failure of a roof drain to adequately remove the water accumulating on a roof surface can result in substantial loads that were not anticipated when calculating the structural integrity of the building. Winter issues such as ice and snow that stop the proper functioning of roof drains has caused structures to collapse. In addition the accumulation of water on roofs causes issues other than unanticipated loading, if frozen the ice can cause additional damage to parapets, crickets, roof scuppers, etc. The accumulation of water on a flat roof due to a malfunctioning roof drain can cause considerable damage. Maintenance workers are constantly attending to roof drains and the removal of the ice and snow is a major maintenance workers responsibility. In addition, for some unknown reason, although the intent is to install the roof drain at the low point of the roof, there are many times, that the drain is not located at the low point and additional tapered insulation or even, the removal replacement of the roof drain is necessary.