The NZ Metal Roof and Wall Cladding Code of Practice is a comprehensive design & installation guide, and a recognised related document for Acceptable Solution E2/AS1 of the NZ Building Code.
Types of gutter:
- External gutters.
- Concealed Fascia-Gutter Systems.
- Internal fascia Gutters.
- Roof Gutters.
- Secret Gutters.
The term “gutters” can be applied to all roof drains, but “spouting” refers specifically to external gutters. External gutters are positioned outside the building envelope. Internal gutters are formed where two connected gables meet at an internal draining point, or inside a parapet wall.
Internal fascia gutter refers to gutters installed directly behind a fascia.
Valleys are formed when two roof planes meet at an angle of less than 180°.
The definition of gutters in the COP includes the troughs of a profile adjacent to an obstruction (such as a penetration) or where a secret gutter is required, i.e., at the barge line of a swiss gable roof.
Roof gutters are formed where a penetration obstructs and concentrates the flow of water, often into a single pan.
A secret gutter is formed where a roof discharges into a raked barge.