Floor drains are primarily used for inside location where the flow rate into the drain can be anticipated and for outside areas where rainfall intensely dictates sizing. Drains should be selected with sufficient to size and grate free area to pass the anticipated flow.
Roof drains normally 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.