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:
- BlueScope Corrosion Technical Bulletin CTB 12 - Dissimilar Metals
- BlueScope Corrosion Technical Bulletin CTB 25 - Inert Catchment
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, Lead & 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 |
| SUPERDURA® 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, SUPERDURA® 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