Box Gutter Overflow Requirements

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

Box gutter overflow requirements.

Have a sole width which is not reduced discharge at the downstream end without. Have a minimum width of 300mm for commercial installations 200mm for domestic installations. 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. If draining to a sump with a vertical overflow somewhere along the box gutter use this calculator.

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

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. This effectively states that all box gutters must allow for 30mm of freeboard which is from the overflow point eg. Use a 10mm spacer this creates a gap behind the gutter so water can overflow freely.

Box gutters must be straight no bends. For commercial projects the minimum allowable width is 300mm. However any width can be entered. Overflow devices need to discharge to the atmosphere in such a way as.

Have a minimum depth of 75mm at the high end.