Exterior Roofs: Zincalume, galvanised steel usually 'corrugated iron'

Surface preparation:

1. Zinc and galvanised steel - Zinc is a reactive material which will corrode to basic zinc carbonate normally, and mixed with basic zinc chloride in coastal areas. The form of the corrosion product is not protective.
   
   Coating of the metal is recommended as soon as possible, definately within four weeks. Washing with detergents and/or emulsifiable solvents is all the surface preparation that is necessary.
   
   Even though the surface is cleaned initially, it cannot be overstressed that roofs in particular need washing down prior to each day's painting, if there is any danger of wind blown salt depositing on the surface. Where corrosion has taken place this must be carefully removed, leaving behind as much of the remaining protective zinc layer as possible. Wet abrasive removal is recommended.

2. Zincalume - is a blend of aluminium and zinc, and behaves predictably somewhere between the two. Although it is much more corrosion resistant than zinc, it is still recommended that it is painted as soon as possible after careful cleaning with Resene Roof Wash and Paint Cleaner.
   
   To wash down, mix one part of Resene Roof Wash and Paint Cleaner with three parts of fresh water. Apply a liberal wash of this mixture to the surface with a nylon bristle brush or broom. Thoroughly scrub the surface to ensure complete removal of all grease, dirt, dust, flaking paint and other contaminants. Rinse thoroughly with fresh water and allow to dry.

First coat:
Wind blown salts on the metal surface, and between coats cause premature corrosion. Always wash the area to be painted with fresh clean water before commencing work. For new work apply one coat of Resene Galvo-Prime.

For repainting work spot prime bare areas with one coat of Resene Galvo One.

For locations in close proximity to the sea, two full coats of Resene Galvo-Prime or Galvo One are recommended.

Topcoats:
Apply two coats of Resene Hi-Glo Acrylic. The choice of Resene Hi-Glo Acrylic Micaceous Iron Oxide based colours will also give superior protection.

Follow label instructions at all times.

Cleaning up:
Cleaning up waterborne paints is different to solventborne paints - click here for detailed instructions on clean up.