NZS 3604:2011 Timber-framed buildings Table 4.3 permits the use of bright steel nails for framing that is enclosed (remains dry). Where that framing is H3.2 treated, the type of fixing depends on the treatment used – CCA, copper azole, or copper quaternary:
- For CCA (preservative code numbers 01 or 02) treated timber – bright steel.
- For copper azole (preservative code numbers 58 or 88) treated timber – hot-dip galvanised (NZS 3604 clause 4.4.4).
- For copper quaternary (preservative code numbers 89 or 90) treated timber – hot-dip galvanised (NZS 3604 clause 4.4.4).
If you’re unsure of the treatment type used for the H3.2 timber, use hot-dip galvanised nails.