Box Gutter Overflow Requirements

Sides must be vertical.

Box gutter overflow requirements.

If draining to a sump with a vertical overflow somewhere along the box gutter use this calculator. Code box gutter requirements. Box gutters must be straight no bends. The hydraulic capacity of the overflow device must be no less than the design flow for the associated box gutter outlet.

For commercial projects the minimum allowable width is 300mm. Have a minimum width of 300mm for commercial installations 200mm for domestic installations. All domestic box gutters must be a minimum of 200mm wide and 75mm deep. The minimum width allowed for domestic projects is 200mm.

Overflow devices need to discharge to the atmosphere in such a way as. For commercial projects the minimum allowable width is 300mm. Have a sole width which is not reduced discharge at the downstream end without. Use a 10mm spacer this creates a gap behind the gutter so water can overflow freely.

However any width can be entered. Have a minimum depth of 75mm at the high end. Rainhead overflow or specific box gutter overflow must be at least 30mm below the height of the back of the box gutter. This effectively states that all box gutters must allow for 30mm of freeboard which is from the overflow point eg.

The vba has provided several options for plumbers to make an installation compliant.