Proposal 3 - VM2 Horizontal spread of fire scenario (HS) changes
The full details of the proposed changes can be found here http://govt.us4.list-manage1.com/track/click?u=026938519db5ea2b4ed25d644&id=45101eed08&e=9231d0b018
You should also respond individually to the MBIE questions which can also be found at the above link.
The proposed change to Table 4.1 removes the old note 3
“3. As an alternative to specifying a cladding meeting the ‘B’ performance level, engineers may calculate the contribution of a combustible cladding to the radiation received at and beyond the relevant boundary to demonstrate the maximum permitted radiation flux criteria specified in the NZBC are not exceeded.”
This would mean that the proposed Table 4.2 which has no cladding restrictions up to 60m when there is no sleeping or other property would be overridden by table 4.1.
Do you think I am interpreting this correctly?
This has implications for any cladding systems such as timber which have neither an A or B rating on buildings over 7m in height. A two storey building is often over 7m in height at the gable end.