Secondary Roof Drainage For Exterior Leaders

The information contained in this manual was created to further the knowledge.

Secondary roof drainage for exterior leaders.

Providing an immediately adjacent secondary overflow drain next to every primary drain with a separate piping system. Secondary emergency overflow roof drains look similar to primary drains but a standpipe or dam blocks water from entering the drain until it reaches a certain depth. This secondary system is a mirror of the primary. As a homeowner you appreciate how costly home repair is and as such it is important to deploy preventive measures to avoid such expenses.

Secondary roof drains or scuppers are required when the roof perimeter extends above the roof surface in such a manner that water will be entrapped if the primary roof drains are clogged. When scuppers are used for secondary emergency overflow roof drainage the quantity size location and inlet elevation of the scuppers shall be sized to prevent the depth of ponding water from exceeding that for which the roof was designed as determined by section 1611 1. Example of a primary secondary roof drain assembly courtesy of zurn. Scuppers shall not have an opening dimension of less than 4 inches.

To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3. Exterior drainage solutions for your home a recent study by the concrete foundation association cfa shows that 85 of home structural damage is caused by poor drainage. The secondary roof drain piping may be installed using the method in either section 1101 11 2 2 1 or section 1101 11 2 2 2. 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.

But this isn t the whole story. Your home is the. Section 101 5 of the ipc tells us not to reduce the pipe size in the direction of flow. Scuppers are typically easier to install.

Principles of exterior drainage short course is a condensed version of the principles of exterior drainage. These will drain to the exterior of the building with downspouts and ultimately discharge at grade to sheet flow or to be hard piped to an underground storm system or detention pond. This reveals that the minimum size for the leader pipe is 5. It focuses solely on all aspects of exterior drainage from the identification of the problem to the design and installation of the solution.

The better choice if it can be accommodated is one of the first two methods where overflow at the exterior of the building roof is provided without the need for secondary drainage piping. Secondary drain provided with min 2 tall water dam. 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. Secondary drains during a roof replacement proj ect.