Secondary Roof Drainage Design

Firstly there is an explanation in the above referenced section for where and why a secondary roof drainage system must be provided.

Secondary roof drainage design.

Example of a primary secondary thru wall drainage to downspout courtesy of ernie s gutter. Otherwise the system will not adhere to the above referenced principle. Ponding instability is avoided. There are 3000 roof collapses a year in the.

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. The secondary roof drains can be of two types roof drains with an independent piping system or roof drains that combine with the primary roof drainage piping which will require an increase in piping size. Following these four steps you can successfully specify the correct size of horizontal and vertical drains required for any roof. Adequate drainage is an important component of a properly installed roof so installing the correct size of drains is essential.

Generally the roof system is more durable. Roof drainage systems tend to be given little attention until they fail. Roof collapses are prevented if primary and secondary drainage systems are designed properly. In either case the discharge shall be located so that it is readily visible by building occupants.

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. Better to design appropriate drainage assemblies and address incipient concerns now than. P 1503 4 1 secondary emergency overflow drains or scuppers. The roof system is less susceptible to leakage.

The drainage system shall incorporate adequate cleanouts placed in a manner that the drainage system may be readily cleaned. Why is roof drainage so important. When installing a secondary roof drainage system a licensed plumber must adhere to the following provisions issued by the board. 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.

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. P 1503 4 roof drainage. Secondary emergency roof drains or scuppers are required according to ipc to prevent a rainwater build up. See section 1107 for yourself.

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. Once the required rainfall data has been determined the primary and secondary roof drainage system must be sized in accordance with. Roof drainage is one of the fundamental considerations of building design.