Minimum Box Gutter Fall

Layout box gutters must.

Minimum box gutter fall.

Box gutter outlets must discharge through either a rainhead or sump. Box gutters should have a minimum fall of 1. If gutters slope too severely they don t hold water and water could splash over the sides in heavy rain. Have a minimum width of 300mm for commercial installations 200mm for domestic installations.

It may be lined with epdm rubber metal asphalt or roofing felt and may be concealed behind a parapet or the eaves or in a roof valley. If gutters don t slope water gathers in them. The amount of collected water increases until it spills over the sides of the gutter. Rainhead overflow or specific box gutter overflow must be at least 30mm below the height of the back of the box gutter.

Overflow box gutters must have independent overflow provision discharging to the atmosphere. The gutter slope also called the pitch is the amount the gutter tilts down to let rainwater flow out of it. I fall or slope box gutters to be installed with a minimum uniform fall of 1 in 200 towards the outlet. Can i change the measurements on this box gutter flashing.

This effectively states that all box gutters must allow for 30mm of freeboard which is from the overflow point eg. Have a minimum depth of 75mm at the high end. Allowable box gutter width slope and length required by the australian plumbing code as nzs 3500 3 2 box gutters allowable width slope and length to as nzs 3500 3 2018 stormwater drainage acceptable solutions.