Sheet Overhang

The maximum overhang for all corrugate and low trapezoidal profiles is 150  mm, unless a product has been specifically tested to withstand point load and design wind loads at a greater overhang.

The allowable overhang distance of various cladding profiles will depend on their section properties.

When using trapezoidal profiles, greater overhangs can be achieved by stiffening the edge of the sheet in various ways; the most common being using a square gutter with a horizontal flange, but this should be fastened on every pan to achieve continuity.

The limit placed on low trapezoidal profiles with a stiffened overhang is 300 mm but it is not suitable for corrugate.

The overhang distance can be increased for some trapezoidal profiles with a rib height greater than 28 mm, but this distance must be proved by testing.

Where the cladding is fixed at a ridge or apron, the overhang distance can be increased to 250 mm from the end of the sheet, as the cladding is not subjected to the same point load or UDL and the load is shared with the flashing.

Point of access and expected roof traffic loads must also be considered.

Draft Clause: