Existing roof paint in poor condition

(flaking paint and red rusting)

Resene Popular Paint Systems –
Roofing products and roof paint preparations: training notes

This web page is an edited version of the Resene Best System Selling training notes provided to Resene staff and is provided to enable you to gain a greater understanding of the substrates and paint systems you may encounter in your decorating project. It is impossible to cover all decorating scenarios in a single document, so if you are in doubt about any aspect of your project please contact Resene for assistance.

How to paint existing roof paint in poor condition
(flaking paint and red rusting)

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

  1. Treat moss and mould with Resene Moss & Mould Killer

  2. Thoroughly scrub using Resene Roof Wash and Paint Cleaner and a hard bristled scrubbing brush. Alternatively wash down using a high pressure waterblaster.

  3. Scrape as necessary

  4. Prime bare areas with Resene Galvo One. Apply second coat to any lightly rusted areas.

  5. Topcoat options:

Existing roof paint in poor condition(flaking paint and red rusting)

1 To optimise the benefits of the Resene Cool Colour topcoat use Resene Cool Primer

Things to consider:

  • What sort of roof do you have?
  • Is your roof painted?
  • How long ago?
  • What is the condition of the roof?
  • Is there flaking paint and/or rust present?
  • Do you live close to the sea, say within 500 metres?
  • What colour do you have in mind?
  • Have you considered Resene Cool Colour paints?
  • What is the floor area of your house?
  • Is access to the roof likely to be a problem?


Roof rust
Roof rust
  • Older roofs that have been neglected often have flaking paint and ‘white’ rust and often some ‘red’ rusted areas. If the roof is badly corroded replacement is often a better option, either the entire roof or in some cases individual sheets.

  • While Resene Rust-Arrest primer is excellent for preparing rusted areas it does not adhere well to the adjacent galvanised surfaces. Resene Galvo One is an excellent compromise, applied in multiple coats to achieve a high film build on any lightly rusted areas.

  • An alternative is to use Resene Alumastic as a spot primer. It comes in 1 litre composite packs for this purpose.

Resene Rust-ArrestResene Alumastic

Key accessories essential to complete the job

  • Extension pole
  • PAL corrugated roller kit (if painting corrugated iron)
  • Resene black 75-100mm brush for cutting in flashings and ends of sheets, Haydn Genius or PAL Legend if painting longrun on trough sections
  • Resene Hot Weather Additive
  • Resene Roof Wash and Paint Cleaner
  • Turps for Resene Galvo One

Add-ons – to make the job easier or quicker

  • Gloves
  • Hand cleaner
  • Paint pots (especially when 10 litre pails are bought)
  • Scraper for removing lichen
  • UV protection

Return to index

Resene Paints Ltd

Resene Paints Ltd   –

We would love to hear from you if you wish to use Resene's images, information and ideas for social medial, blogs, newsletters and other media use. Please email and let us know what you need, what it is for and how Resene will be acknowledged as the source of the content. We are happy to assist with most requests.

Our vision is to be respected as a trusted, ethical and sustainable company and acknowledged as the leading provider of innovative paint and colour technology. View Resene’s profile, Quality Policy, Environmental Policy and Health & Safety Policy.

Any personal data, such as name, address, phone, email details, supplied to Resene for the purposes of receiving newsletters, orders etc will be retained by Resene Paints Ltd and used only by Resene Paints Ltd and its trusted agencies for the purposes of communication/promotion/providing service to you. We do not sell, trade or otherwise transfer your personal data to outside third parties. If you wish to opt out of communication from Resene please complete our contact us form. View our full Privacy Policy.

Colours shown on this website are a representation only. Please refer to the actual paint or product sample. Resene colour charts, testpots and samples are available for ordering online.   See measurements/conversions for more details on how electronic colour values are achieved.

View Videos