Internal Roof Drainage

Properly slope the structural framing and deck minimum inch per foot.

Internal roof drainage.

Unlike scupper or gutter drainage systems in which water flows off the side of the roof internal systems allow for drains to be strategically placed throughout a roof deck to ensure water doesn t pool. The drainage requirements for flat roofs on buildings present some special problems that we describe and illustrate here. This is a drainage point that can be installed across the roof s surface even in the centre of the roof. At page top and at left our photos show a low slope roof surrounded by a parapet.

Use an insulating fill or tapered insulation for slope. Properly locate roof drains scuppers and gutters to remove water from the roof s surface. Internal roof drains these will drain to somewhere near the center of the roof and down through the building to underground storm mains or a detention pond. Roofs of this design will have one or more roof drains or scuppers installed.

Watch for clogs blockage at the roof drain or scupper. If water collects in one spot in the middle of your roof then installing an interior drain there to move the water is a good solution. The most important factors in roof drain design are. On large flat roofs mainly on commercial buildings or large residential complexes you ll likely find internal drainage systems.