01 / Select Materials
NZ Construction Context: NZ's coastal and marine environments accelerate galvanic corrosion. Salt spray is highly conductive and dramatically increases corrosion rates. Stainless steel fixings are mandatory in Zone D (severe coastal) per NZS 3604. Copper run-off onto zinc/aluminium is particularly problematic.
02 / Compatibility Result
Compatible
These materials have similar galvanic potentials and can be safely used together in most conditions.
Carbon Steel
⟷
Carbon Steel
Galvanic Series Reference
Safe (<0.15V difference)
Caution (0.15–0.25V)
Avoid (>0.25V)
Material 1
Material 2
| Metal | Anodic Index (V) | Category |
|---|
Atmospheric Corrosion Only: This tool applies to atmospheric conditions (roofing, cladding, gutters, fixings) in NZ environments. It does not apply to submerged or buried conditions. Results are based on galvanic compatibility for atmospheric exposure — refer to NZS 3604 and E2/AS1 Section 9 for exposure zone (B, C, D) and cladding/flashing compatibility guidance. For specific project advice, consult a Chartered Professional Engineer.
Limitation of NZBC E2 Table 21: E2's compatibility table does not account for area ratio effects — the relative size of the anode versus cathode is critical in practice. A small galvanised fastener into a large aluminium panel (small anode, large cathode) is a documented NZ failure mode that E2 Table 21 permits but which carries high risk. This tool's area ratio selector and pair-specific notes aim to address these gaps. Where results differ from E2 Table 21, the more conservative outcome should be applied.
Limitation of NZBC E2 Table 21: E2's compatibility table does not account for area ratio effects — the relative size of the anode versus cathode is critical in practice. A small galvanised fastener into a large aluminium panel (small anode, large cathode) is a documented NZ failure mode that E2 Table 21 permits but which carries high risk. This tool's area ratio selector and pair-specific notes aim to address these gaps. Where results differ from E2 Table 21, the more conservative outcome should be applied.