BOX GUTTER AND RAIN WATER HEAD DESIGN TO AS/NZS 3500.3: 2015
Design Storm Intensity I = mm/hr
Horizontal catchment area Ah = sq.m
Roof slope S = degrees
from AS 3500 fig 3.3(a),  Vertical Area Av =
= sq.m
from eqn 3.4.3(1),  Catchment Area Ac = Ah+0.5*Av
= sq.m
Flow Q = I*Ac/3600 Litres/sec
= Litres/sec
From fig I1 (Interpolating where necessary)
using:- Gutter Slope 1 in
 and Gutter Width W = mm
from fig I1 Minimum Gutter Depth d = mm
from fig I1 gutter depth at 1:200 d = mm

Rain Water Head Calculations

Selected down pipe size dia = mm
From fig I3, Rain water head Depth = mm
From fig I3, Rain water head Length at slope 1:200 = mm
Rain water Head Width = mm

Summary

Down Pipe Size = mm
Box Gutter Width = mm
Box gutter minimum Depth = mm
Rain Water Head Depth = mm
Rain Water Head Length = mm
Rain Water Head Width = mm
James Crint
Head Honcho
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