ZINCALUME® steel (and COLORBOND® steel manufactured with a ZINCALUME® steel substrate), are NOT recommended for immersion in wet cement as rapid corrosion and degradation of the coating alloy will occur. The recommended product for use with uncured concrete and highly alkaline bonding materials is galvanised steel.
COLORBOND® steel is available with a galvanised substrate - one common use being posts for fencing.
The construction of gardens adjacent to buildings or fencing by placing soil directly against ZINCALUME® steel or COLORBOND® steel sheeting is strongly discouraged as corrosion of the sheeting will rapidly occur about the area covered with soil.
Moisture or moisture retaining materials should not be permitted to remain in intimate contact with ZINCALUME® steel, COLORBOND® steel or galvanized steel. Such contact will ultimately result in corrosion of the material.
The major factors influencing corrosion are the continual retention of moisture and the differential concentration of oxygen at the material surface. Gutters are frequent victims, with insufficient fall leading to ponding of water.
The accumulation of debris (leaf matter, dirt etc) which results in continual immersion, is the most common reason for unsatisfactory performance of guttering.
In typical garden applications such as fence panels, garden sheds and walling the build up of grass cuttings, leaves, soil from gardens, mulch, compost, sand and ashes must be avoided.
For more information, please Download Corrosion Technical Bulletin CTB 16 - Immersion.