Box Gutter Overflow Design

There will also be an overflow facility on the side or the end.

Box gutter overflow design.

Eaves and box gutters. The box gutter depth and the sump length are influenced by the size of the overflow. Drill rivet holes for the gutter splash guard. Box gutters sit within the façade or structure of the building.

Outlets box gutter outlets must discharge through either a rainhead or sump. Support the entire weight of the gutter and sumps when full of water as well as a trafficable load at any point in the gutter and sumps. There are two categories of gutters. All domestic box gutters must be a minimum of 200mm wide and 75mm deep.

The hydraulic capacity of the overflow device must be no less than the design flow for the associated box gutter outlet. Rainhead overflow or specific box gutter overflow must be at least 30mm below the height of the back of the box gutter. However a wider overflow may increase the length of the sump. A good box gutter design will have falls along its length together with sumps to collect water before it is fed into large downpipes.

A wider overflow needs less depth of overflow hence the box gutter depth will also be reduced. This effectively states that all box gutters must allow for 30mm of freeboard which is from the overflow point eg. Overflow devices need to discharge to the atmosphere in such a way as to prevent damage to buildings and property. This is very important so that water will overflow externally to the building rather than flood into the roof cavity.

Layout box gutters must. Making the box gutter wider will also reduce the box gutter depth. You can find these precut gutter splash guards about 3 in brown and white aluminum at a home center but you could easily make your own out of aluminum or sheet metal and spray paint them to match your gutters. Eaves gutters form the outer perimeter of the roof and their shape allows excess water in high rainfall events to safely overflow over the outside lip of the gutter.

Sump with a side overflow device. 2015 3 7 4 layout. Failing to install appropriately designed box gutters and correctly sized and positioned overflow devices can lead to serious damage to buildings and contents especially in shed and flat house roof designs often resulting in hefty insurance claims which are a total burden.