Compatibility with Non-Metallic Substances

Timber is generally acidic, although some timbers—such as cedar—are more acidic than others. The interaction between preservative treated timber and metal depends on the moisture content of the timber, the time of wetness and the type of treatment. The corrosion rates of metal in contact with wet CCA-treated timber and with untreated radiata are similar.

Neither AZ coated steel nor aluminium should be used as a flashing embedded in concrete or masonry.

Butyl Rubber in Wet Contact with Cladding

Butyl Rubber contact
Butyl rubber in wet contact with coated aluminium and steel has been found to accelerate corrosion.
Revision Category: 
4 - Clause Inserted
Revision Detail: 

A new clause, previously part of "4.10.3 Compatibility Table". Information was split since this is not part of the table or online tool.