Menu

Overflows

Overflows must discharge clear of the building to clearly show that downpipe capacity has been exceeded; it should be an obvious indication that the gutters need maintenance.

A scupper outlet to a rainwater head must have a cross-sectional area equal to 1½ times that of the downpipe outlet. The bottom of the overflow must be no higher than 25 mm below the bottom of the spouting.

Where the position of an outlet of a parapet wall gutter is on an outside wall, any scupper outflow should discharge into a rainwater head.

Clause: 
005_006_003_000_000_000_000_000_000
Clause Number: 
5.6.3
/cop/roof-drainage/rainwater-heads-sumps-and-overflows#overflows
Revision Category: 
3 - Substantial change to recommendation
Revision Detail: 

Changed the recommended cross-sectional area of a scupper to align with BRANZ recommendation.

Draft Clause: 
005_008_002_000_000_000_000_000_000