KOROK® External Wall Systems
- Appraisal number 722 (2020)
- Valid from
- Information provider
- BRANZ Limited
- Information type
- BRANZ Appraisal
KOROK® External Wall Systems incorporate KOROK® panels that are used to construct non-loadbearing, standard, fire and acoustically rated vertical straight external walls without penetrations.
The KOROK® panel forms the exterior cladding of the KOROK® EX1 and EX2 systems. The KOROK® EX3, EX4 and EX5 systems require protection with a suitable cladding system as specified in the technical literature for KOROK® External Wall Systems.
KOROK® panels are available in two panel profiles (KOROK® Gen 1 and KOROK® Gen 2 panel) and are made from lightweight aerated concrete encased in profiled galvanised sheet steel. For the KOROK® Gen 1 panel profile, paint-coated steel coil may also be used for one or both faces.
KOROK® External Wall Systems have been appraised for use as vertical straight, single-skin flat walls (EX1 and EX2 systems), including walls requiring overcladding (EX3, EX4 or EX5 systems). All these wall systems may be used as non-loadbearing, standard and fire rated external walls for all buildings of importance levels 1 to 5 as defined by AS/NZS 1170, except that housing and communal residential buildings are excluded and for walls with no penetrations.
Note: Exterior cladding systems used for the KOROK® EX3, EX4 and EX5 systems have not been assessed and are outside the scope of this Appraisal.
KOROK® EX1 and EX2 Systems have been appraised for weathertightness and structural wind loading when used as a cladding solution for buildings situated in specific design wind zones with maximum differential ultimate limit state (ULS) air pressure of up to 1.76 kPa.
When used with KOROK® External Wall Systems, the KOROK® panels are installed in a vertical orientation. The maximum unsupported span for the panels between structural supports is 8 m. The overall height or length of a KOROK® External Wall Systems wall will be determined by the structural support. When used as part of a fire rated system, the maximum unsupported spans of the KOROK® panels in vertical orientation are:
- 4 m for the EX1 and EX2 systems; and
- 6 m for the EX3, EX4 and EX5 systems.
Note: Greater spans are subject to specific engineering design and/or fire engineering assessment and are outside the scope of this Appraisal.
KOROK® External Wall Systems are suitable for use in NZS 3604 Exposure Zones B, C and D. Refer to Table 2 of this Appraisal for more detailed durability information.