The rationale for not requiring secondary drainage is that if positive drainage is provided that is adequate to drain the roof.
Secondary roof drain code requirements.
Using ibc 2009 or ibc 2012 it could be inter preted the addition of secondary drainage may be required during reroofing this was not the intent of the 2009 code change.
The uniform plumbing code followed a similar path to incorporating secondary drainage requirements.
Part a d1 1 d notes that.
See section 1107 for yourself.
Once the number of required drains for the area is determined the size of the drain inserts and plumbing should be established.
Where roof drains are required secondary emergency overflow roof drains or scuppers shall be provided where the roof perimeter construction.
Prior to the 1994 upc the only mention of secondary roof drains is a listing of the materials to be utilized for over flow drains in the 1994 upc rainwater systems was included as appendix d to the code.
1511 1 roof assemblies and rooftop structures general.
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.
We would like to show you a description here but the site won t allow us.
Secondary drainage was not required with ibc s previous editions.
If they are used for secondary drainage then they should be a minimum of 2 inches above the roof level and a maximum of 4 inches above the roof level.
Firstly there is an explanation in the above referenced section for where and why a secondary roof drainage system must be provided.
This system shall be compliant with all federal state and local codes.
Ibc s secondary roof drainage requirement first was added in ibc 2009.
Secondary emergency roof drains or scuppers are required according to ipc to prevent a rainwater build up.
The minimum slope the code allows is in 12 in.
This is completed using a plumbing calculation.
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.
It s very short and to the point.
Building code 2015 of wyoming 15 roof assemblies and rooftop structures 1503 weather protection 1503 4 roof drainage 1503 4 1 secondary emergency overflow drains or scuppers.