Box Gutter Overflow Requirements

All domestic box gutters must be a minimum of 200mm wide and 75mm deep.

Box gutter overflow requirements.

If draining to a sump with a vertical overflow somewhere along the box gutter use this calculator. The vba has provided several options for plumbers to make an installation compliant. The minimum width allowed for domestic projects is 200mm. Rainhead overflow or specific box gutter overflow must be at least 30mm below the height of the back of the box gutter.

For commercial projects the minimum allowable width is 300mm. Code box gutter requirements. Trial box gutter width the minimum width allowed for domestic projects is 200mm. Have a sole width which is not reduced discharge at the downstream end without.

The hydraulic capacity of the overflow device must be no less than the design flow for the associated box gutter outlet. Box gutters must be straight no bends. Hang the gutter lower the top of the bead must be 20mm below the top of the fascia to allow water to overflow safely over the bead. Have a minimum width of 300mm for commercial installations 200mm for domestic installations.

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. However any width can be entered. The width of the rainhead is to be at least equal to the width of the box gutter and the box gutter needs to be sealed to the rainhead.

Overflow devices need to discharge to the atmosphere in such a way as.