Contact with (or run-off from) some materials can damage coated steel products. The materials include certain metals, treated timbers and chemicals. As a consequence:
- Don’t allow any contact of coated steel products with incompatible materials. (See table DD DCM A 001)
- Don’t allow discharge of rainwater from incompatible materials onto coated steel products. (See table DD DCM AD 001)
- Ensure that supporting members are compatible with the coated steel products or alternatively are appropriately coated.
If there are doubts about the compatibility of other products being used, seek advice from your nearest Fielders Branch. Incompatible materials include:
- lead
- copper
- monel metal
- bare steel
- stainless steel (except with COLORBOND® stainless cladding)
- carbon (in pencils and some rubbers)
- green or some chemically-treated timber (like CCA or tanalith treatments)
- materials subject to cycles of dryness and wetness or which have excessive moisture content (such as improperly-seasoned timber)
- wet and dry concrete
- soils
- vegetable matter
- cleaning agents (e.g. brick cleaning)
- any material which will inhibit normal exposure to the atmosphere
Compatibility of Direct Contact Between Metals
| Roof Drainage System Components and any Cladding Material | Accessory or Fastener Material | |||||||||||||||||
| ZINCALUME® Steel | Galvanised Steel | Zinc | COLORBOND® Steel (Plus Ultra, Metallic & Matt) | SuperDura™ Stainless Steel | Stainless Steel (300 series) | Aluminium Alloys | Copper and Copper Alloys* | Lead2 | ||||||||||
| Atmospheric classification | ||||||||||||||||||
| SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | SI and VS | Mild | |
| Aluminium Alloys | No4 | No4 | No4 | No4 | No4 | No4 | No4 | No4 | No4 | No4 | Yes3 | Yes3 | Yes | Yes | No | No | No | No |
| ZINCALUME® Steel | Yes | Yes | Yes1 | Yes1 | Yes1 | Yes1 | Yes | Yes | No | Yes | No | Yes | Yes | Yes | No | No | No | No |
| Galvanised Steel | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | No | Yes | Yes | Yes | No | No | No | Yes |
| Zinc | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | No | Yes | Yes | Yes | No | No | No | Yes |
| COLORBOND® Steel (Plus Ultra, Metallic & Matt) | Yes | Yes | Yes1 | Yes1 | Yes1 | Yes1 | Yes | Yes | No | Yes | No | Yes | Yes | Yes | No | No | No | No |
| SuperDura™ Stainless Steel | No | No | No | No | No | No | No | No | Yes | Yes | Yes | Yes | No | No | No | No | No | No |
| Stainless Steel (300 series) | No | No | No | No | No | No | No | No | Yes | Yes | Yes | Yes | No | No | No | No | No | Yes |
| Copper and Copper Alloys | No | No | No | No | No | No | No | No | No | Yes | No | Yes | No | No | Yes | Yes | No | Yes |
| Lead2 | No | No | No | Yes | No | Yes | No | No | Yes | Yes | Yes | Yes | No | No | Yes | Yes | Yes | Yes |
Legend:
SI, VS, Mild = Severe industrial, very severe and mild classifications (see AS/NZS 2312).
Yes = Acceptable - as a result of bimetallic contact, either no additional corrosion of rainwater goods will take place, or at the worst, only very slight additional corrosion. It also implies that the degree of corrosion would not significantly shorten the service life.
No = Not acceptable - moderate to severe corrosion of rainwater goods will occur, a condition which may result in a significant reduction in the service life.
Note:
- Unpainted zinc-coated steel and zinc are suitable for direct contact but should not receive drainage from an inert catchment.
- Due to its toxicity, lead is not recommended for rainwater goods.
- Fixings only.
- Our experience is that these materials are not compatible in corrosive environments so our advise differs from AS/NZS 3500.3:2015 Table 4.4.1
Compatibility of Drainage from an Upper Surface to a Lower Metal Surface
| Lower Roof Drainage System Material | Upper Cladding or Roof Drainage System Material | |||||||||
| ZINCALUME® Steel | Galvanised Steel | Zinc | COLORBOND® Steel (Plus Ultra, Metallic & Matt) | SuperDura™ Stainless Steel | Stainless Steel (300 series) | Aluminium Alloys | Copper and Copper Alloys | Lead2 | Glazed Roof Tiles, Glass and Plastic | |
| Aluminium Alloys | No4 | No4 | Yes | No4 | Yes5 | Yes5 | Yes | No | No4 | Yes |
| ZINCALUME® Steel | Yes | Yes | Yes | Yes | Yes5 | Yes5 | Yes | No | No | Yes |
| Galvanised Steel4 | No | Yes | Yes | No | No | No | No | No | Yes5 | No |
| Zinc | No | Yes | Yes | No | No | No | No | No | Yes5 | No |
| COLORBOND® Steel (Plus Ultra, Metallic & Matt) | Yes | Yes | Yes | Yes | Yes5 | Yes5 | Yes | No | No | Yes |
| SuperDura™ Stainless Steel | Yes5 | Yes5 | Yes5 | Yes5 | Yes | Yes | Yes5 | Yes5 | Yes | Yes |
| Stainless Steel (300 series) | Yes5 | Yes5 | Yes5 | Yes5 | Yes | Yes | Yes5 | Yes5 | Yes | Yes |
| Copper and Copper Alloys | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes | Yes | Yes |
| Lead2 | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes5 | Yes | Yes |
Legend:
Yes = Acceptable - as a result of bimetallic contact, either no additional corrosion of rainwater goods will take place, or at the worst, only very slight additional corrosion. It also implies that the degree of corrosion would not significantly shorten the service life.
No = Not acceptable - moderate to severe corrosion of rainwater goods will occur, a condition which may result in a significant reduction in the service life.
Note:
- Unpainted zinc-coated steel and zinc are suitable for direct contact but should not receive drainage from an inert catchment.
- Due to its toxicity, lead is not recommended for rainwater goods.
- Fixings only.
- Our experience is that these materials are not compatible in corrosive environments so our advise differs from AS/NZS 3500.3:2015 Table 4.4.1
- Although drainage between the materials shown would be acceptable, direct material contact should be avoided.