New galvanised steel or Zincalume (up to six months old)

Refer to the PDF flowchart for a visual of the steps below:

1. Wash thoroughly using Resene Roof and Metal Wash (D88) then rinse thoroughly.

2. Apply Resene Galvo-Prime (D402) or Resene Galvo One (D41) (2 coats for severe marine environment).

3. Wash between coats if windblown salt is present. See notes.

4. Topcoat:

   1. Apply 2 coats of Resene Summit Roof Semi-Gloss (D315S) or for spray application Resene Summit Roof Commercial Spray Satin (D315S) in either the standard colour or CoolColour (D315SC) if available in your chosen colour.

   2. If a higher sheen is desired, apply Resene Hi-Glo (D31) gloss or Resene Hi-Glo CoolColour (D31C) gloss.

Things to consider:

• What sort of roof do you have?
• Do you live close to the sea, say within 500 metres?
• What is the floor area of your house?
• What colour do you have in mind?
• Have you considered Resene CoolColour paints to help reflect more heat?

Notes:

• New galvanised steel is much less common today than 15 years ago. In the roofing market it has largely been replaced by Zincalume, which is a blend or mixture of zinc (also used for galvanising) and aluminium.

• During the manufacturing process (often called ‘forming’), an oil or thin acrylic coating is applied to the surface of each sheet. This layer will remain on the surface until it either erodes away after exposure to the weather, which may take a year or more, or it is removed manually. This is why Resene Roof and Metal Wash is recommended for new Zincalume or galvanised steel. The primer must be applied to the metal surface, so any unremoved form oil or acrylic layer will inevitably lead to the paint delaminating or falling off.

• Prime the overlap areas of the roof top and bottom before a new roof is put up. Typically these areas are the first to corrode.

• Where possible, Waterborne Resene Galvo-Prime may be used in place of solventborne Resene Galvo One. It is easier to use and performs as well, or better on new iron. However, the older the iron, the more likely it is there will be corrosion of the zinc and aluminium. This is often called white rust. Use Resene Galvo One on white rust as it is more effective than Resene Galvo-Prime.

• If two coats of primer are required, it is fine to mix and match. Resene Galvo-Prime may be applied over Resene Galvo One but not vice versa.

• Rinse off any salt deposited on the roof between coats or after preparation. In practice, this means if the roof is near the sea and it’s been windy (usually an on-shore breeze), hose the roof down and allow to dry before applying the next coat.

• Consider using a Resene CoolColour to minimise heat retention if selecting a dark colour. Resene CoolColours have also demonstrated improved durability over standard formulations.

• Resene Summit Roof Commercial has a limited colour range but has been specifically developed for spray application. If you need to brush small areas of Resene Summit Roof Commercial, add Resene Summit Roof Commercial Brushing Additive. Resene Summit Semi-Gloss may also be sprayed but you will need to add Resene Summit Roof Spray Additive.

Key accessories essential to complete the job

• Resene Roof and Metal Wash
• Quality extension pole
• PAL corrugated roller kit (if painting corrugated iron). Alternatively, trials have shown that the PAL DeckMaster can also be used.
• A good quality brush:
  • 88-100mm PAL Legend or Basil Hybrid Brush for confident DIYers or those with larger hands.
  • 63-88mm PAL Legend or Basil Hybrid Brush for flashings etc, for those new to DIY or if you have smaller hands.
• Resene Hot Weather Additive
• Turps if Resene Galvo One is used
• Resene Summit Roof Spraying Additive (if needed)

Add-ons – to make the job easier or quicker

• Gloves
• Paint pots
• Resene Umbrella Additive
• Resene Hot Weather Additive

If applying in cooler conditions (under 10 degrees), add Resene Wintergrade Additive to Resene Summit Roof to enable it to dry down to three degrees. Or if rain showers are predicted, consider using Resene Umbrella Additive.

Note: Do not use Resene Wintergrade Additive and Resene Umbrella Additive in the same product. If needed, use one or the other, but not both.

Ask a Paint Expert  |  Ask a Colour Expert  |  Visit your local Resene ColorShop

View product range  |  Choose colours: Colour charts  |  Colour library  |  Book a colour consultation

Painting guide for roofs   How to paint your home