Primary Roof Drain Outfall

The runoff area from the roof and the lawn do not get combined into one total square footage.

Primary roof drain outfall.

Roof drains from zurn include combination primary overflow control flow dual outlet siphonic retrofit and more which cater from educational to commercial needs. Siphonic primary roof drains. Wh 300 400 500 600 siphonic primary roof drain. Wade siphonic drainage design request click here options and variations.

A primary drainage system consists of a network of lateral drains that carry water to a main drain or outfall and away from the playing surface. Roof drains are generally installed on flat roofs or roofs surrounded by parapet walls. Primary drainage systems also form the infrastructure for any subsequent secondary systems. This can be accomplished in a variety of ways.

Main roof drain medium area office buildings overflow parks recreational areas penthouse small area. Submittal specification sheets. A roof surface with a slope of inch per foot 0 0208 rad or greater towards points of free drainage is not a susceptible bay. Section 1611 2 ponding instability states.

Each downspout will drain approximately 500 square feet 2000 sf 4 of roof runoff. The back left portion of the lawn is also included in drainage zone a. Pitched roofs not surrounded by parapet walls are generally drained by gutters. On which water is impounded in whole or in part and the secondary drainage system is functional but the primary drainage system is blocked.

However water from the road drainage system is likely to discharge to the ditch long before that from the adjacent land the time of concentration being a matter of minutes for the road drainage system and hours for the adjacent unpaved areas. This portion of the lawn is 900 square feet 30 x 30. Wh 300 400 500 600 siphonic primary roof drain. Siphonic roofdrain with debris guard.

In brief and simply put design and installation of roof drainage system code sections require roofs to have two separate storm drainage systems i e a primary drainage system and an emergency secondary drainage system and that each system be capable of safely handling 100 of the rain associated with one hour storms having a 0 01 annual probability of occurrence that is a rain that comes around on average about once every 100 years. For a flat roof with interior located drains with or without a parapet it is necessary to assure that failure of any or all the primary drains will not overload the roof with water.