Metal Compatibility Building Codes & Rules

Metal B

Metal E

Metal I

Metal G

Metal H

Aluminium Alloy Properties^{Manufacturer's Recommendation - -, -}

• Lightweight but also strong
• Can withstand harsh weather
• May be used for HVAC ducts, roofing, ceilings, walls, & window frames
• Compatible with ceramic or organic-coated fasteners

F4

Metal A

Metal D

F1

F2

F3

Run-off

Metal C

Run-off

Galvanic Action^{Manufacturer's Recommendation - -, -}

• Process where a metal corrodes during electrochemical contact with another metal
• Corrosion occurs between metals during
• Significant difference in galvanic potential
• Direct contact
• Run-off connecting the metals (due to conductive electrolytes)

Factors Affecting Corrosion^{Manufacturer's Recommendation - -, -}

• Aggressiveness of environment
• Chemical & physical homogeneity of the materials
• Surface area ratio of differing metals
• Formation of metal oxide layer
• Utilizing corrosion inhibitors
• Chemical reactions

Corrosion Prevention^{Manufacturer's Recommendation - -, -}

• Accurate material pairing
• Avoid moisture contact
• Refrain from pairing small base metals with large noble metals
• Insulate the metals
• Use protective coatings
• Utilize gravity, locate cathodes downstream of anodes

Nobility^{Manufacturer's Recommendation - -, -}

• Noble metals are able to resist corrosion
• Base metals have a tendency to corrode

Run-off

^{HB 39:2015, 2.3AS/NZS 3500.3:2021, 2.7.1.4Manufacturer's Recommendation - -, -}