Ings that do not have secondary roof drainage provisions such as overflow drains and overflow scuppers.
Irc roof drains.
Scuppers shall not have an opening dimension of less than 4 inches 102 mm.
The result is the number of drains needed.
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.
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.
In practice it is safer to use 1 4 of fall per foot to ensure proper drainage and provide some wiggle room for error.
Therefore the irc also recognizes scuppers as being an acceptable method of roof drainage.
From a practical standpoint it makes sense as in my.
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.
Where required for roof drainage scuppers shall be placed level with the roof surface in the wall or parapet.
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.
In these instances new secondary drain.
50 000 4 400 11 36.
Take the roof s total square footage and divide by the total square footage handled by one drain.
The imc dictates a 1 minimum pitch of the drain which is equal to 1 8 fall for every 12 foot of horizontal run.
In irc 2015 and its previous editions roof assemblies are addressed in chapter 9 roof assemblies.
Section 2003 irc r903 4 roof drainage states.
Within irc s chapter 9 section r908 reroofing addresses reroofing.
The determination of ponding instability is typically done by an iterative structural analysis where the incremental deflection is determined and the resulting increased rain load from the deflection is added to the original rain load.
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.
In such situations an ice barrier is required to prevent dammed meltwater from penetrating through the roof assembly and into the interior spaces.
For some roof assemblies in cold climates ice may form along eaves which may impede the drainage of meltwater from higher up on the roof surface.
Or 12 drains required.