Compatibility of Materials for Direct Contact and Drainage

Compatibility of Materials for Direct Contact and Drainage

An important consideration in choosing materials for any project is whether those materials are compatible with each other from a corrosion perspective. In most builds, there are two key scenarios to consider: direct contact of materials (e.g. accessories and fasteners in contact with cladding) and drainage of water from one material to another (e.g. water running from a roof to a gutter or cladding).

The two tables below give clear guidance on the compatibility of building materials for direct contact and drainage scenarios.

For further information please refer to BlueScope Corrosion Technical Bulletins or contact BlueScope:

Compatibility of Materials for Direct Contact

  Accessory or Fastener Material
Material Zn-coated steel & zinc Stainless Steel (300 Series) AM-coated steel Aluminium Copper, Brass & Monel Carbon Black**
COLORBOND® steel Yes* No Yes Yes No No
COLORBOND® steel Matt Yes* No Yes Yes No No
COLORBOND® Metallic steel Yes* No Yes Yes No No
COLORBOND® Ultra steel Yes* No Yes Yes No No
COLORBOND® Stainless steel No Yes No No No No
TRUECORE® steel Yes* No Yes Yes No No
ZINCALUME® steel Yes* No Yes Yes No No
Zn-coated steel & zinc Yes No Yes* Yes* No No
  • * Inert catchment situation may apply

  • ** As found in some washers, roof penetration flashings and black "lead" pencils etc.

  • Zn-coated steel = Zinc-coated steel, e.g. GALVASPAN® steel

  • AM-coated steel = Aluminium / Zinc / Magnesium alloy coated steel, e.g. ZINCALUME® steel, TRUECORE® steel

Compatibility of Materials for Drainage

 

Upper Cladding or Rainwater Goods Material

Lower Cladding or Rainwater Goods Material

Prepainted steel

Zn-coated steel & Zinc

AM-coated steel

Aluminium alloys

Stainless steel (300 series)

Copper & copper alloys

Prepainted steel

Yes

Yes

Yes

Yes

No

No

Zn-coated steel & Zinc

No

Yes

No

No

No

No

AM-coated steel

Yes

Yes

Yes

Yes

No

Aluminium alloys

Yes

Yes

Yes

Yes

No

Stainless steel (300 series)

Yes

Copper & copper alloys

Yes

  • † = Whilst drainage between the materials shown would be acceptable, direct contact should be avoided

  • Yes = acceptable

  • No = not acceptable

  • Prepainted steel: including COLORBOND® steel, COLORBOND® steel Matt, COLORBOND® Metallic steel, COLORBOND® Coolmax® steel, COLORBOND® Ultra steel, COLORBOND® Stainless steel

  • Zn-coated steel = Zinc-coated steel, e.g. GALVASPAN® steel

  • AM-coated steel = Aluminium / Zinc / Magnesium alloy coated steel, e.g. ZINCALUME® steel

Acknowledgements

Source: BlueScope media release