Secondary Roof Drainage Design

Better to design appropriate drainage assemblies and address incipient concerns now than.

Secondary roof drainage design.

From the very dawn of building construction it has been necessary to incorporate some method of gathering and discharging rainwater from the roof of a structure. Design and installation of roof drainage systems shall comply with section 1503 of this code and sections 1106 and 1108 as applicable of the international plumbing code. 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. Why is roof drainage so important.

Following these four steps you can successfully specify the correct size of horizontal and vertical drains required for any roof. Roof collapses are prevented if primary and secondary drainage systems are designed properly. Secondary drainage shall be provided through the use of sidewall scuppers or internal roof drains. Secondary emergency roof drains or scuppers are required according to ipc to prevent a rainwater build up.

Example of a primary secondary thru wall drainage to downspout courtesy of ernie s gutter. The roof system is less susceptible to leakage. Once the required rainfall data has been determined the primary and secondary roof drainage system must be sized in accordance with. P 1503 4 1 secondary emergency overflow drains or scuppers.

Roof drainage systems tend to be given little attention until they fail. It s very short and to the point. See section 1107 for yourself. Otherwise the system will not adhere to the above referenced principle.

Considering the damage water can do when allowed to pond on roofs and overflow from gutters it is clear that ignoring roof drainage issues can lead to urgent problems. 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. Roof drainage is one of the fundamental considerations of building design. In many cases early structures were designed primarily as a shelter from the rain their very purpose was to redirect rainfall and maintain a particular area.

When installing a secondary roof drainage system a licensed plumber must adhere to the following provisions issued by the board. There are 3000 roof collapses a year in the. P 1503 4 roof drainage. In either case the discharge shall be located so that it is readily visible by building occupants.

Ponding instability is avoided. Generally the roof system is more durable. Firstly there is an explanation in the above referenced section for where and why a secondary roof drainage system must be provided.