Secondary Roof Drain Code Requirements

When a secondary roof drainage system is installed it shall discharge independent of the primary building storm system and shall terminate a minimum of 18 above grade in an area that will be visible to the people who occupy the building.

Secondary roof drain code requirements. Hydraulic loads from roofs or paved surfaces 1 except as provided in sentence 2 the hydraulic load in litres from a roof or paved surface is the maximum 15 min rainfall determined in conformance with mmah supplementary standard sb 1 climatic and seismic data multiplied by the sum of. The inlet elevation of secondary overflow drains and the invert elevation of overflow scuppers should be not less than 2 inches 51 mm or more than 4 inches 102 mm. The uniform plumbing code followed a similar path to incorporating secondary drainage requirements. Exception 1 of section 1511 1 states existing roofs do not have to meet the requirements of the code if positive drainage is provided.

The rationale for not requiring secondary drainage is that if positive drainage is provided that is adequate to drain the roof. Secondary roof drainage q a this website requires certain cookies to work and uses other cookies to help you have the best experience. This system shall be compliant with all federal state and local codes. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures.

Scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by section 1101 7 scuppers shall have an opening dimension of not less than 4 inches 102 mm. The code defines the term positive drainage similarly to nrca providing for drainage of the roof within 48 hours of precipitation. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. The ontario building code hydraulic loads from roofs or paved surfaces 7 4 10 4.

In these instances new secondary drain. Secondary emergency roof drains or scuppers are required according to ipc to prevent a rainwater build up. A second exception applies to existing build ings that do not have secondary roof drainage provisions such as overflow drains and overflow scuppers. Secondary emergency roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water will be entrapped if the primary drains allow buildup for any reason.

The minimum slope the code allows is in 12 in. Secondary emergency roof drain systems shall be sized in accordance with section 1106 based on the rainfall rate for which the primary system is sized.