4715.2760 ROOF AND DECK DRAINS.
Roof drain strainers.
All roof areas, except those draining to hanging gutters, shall be equipped with roof drains having strainers extending not less than four inches above the surface of the roof immediately adjacent to the roof drain. Strainers shall be provided on all overflow roof drains and shall have an available inlet area, above roof level, equal to that of the conductor or leader to which the drain is connected.
Exceptions: For roof drains with integral overflow drains meeting Standard IAPMO IGC 187-05, a strainer with a minimum height of three inches shall be provided and the structural design of the roof for maximum ponding and the design of the engineered roof drain sumps shall be certified by a state-licensed professional structural engineer.
For overflow drains refer to chapter 1305, Minnesota Building Code.
Flat deck and area drains.
Drain strainers for use on sun decks, and similar area, normally serviced and maintained, may be of the flat surface type, level with the deck and shall have an available inlet area of not less than two times the area of the conductor or leader to which the drain is connected.
Roof drain flashings required.
The connection between roofs and roof drains which pass through the roof and into the interior of the building shall be made watertight by use of proper flashing material.