Why weatherboard painting fails
Common causes include painting over loose coatings, exposed timber that was not properly primed, moisture movement, poor cleaning and coating in unsuitable weather. A fresh topcoat cannot stabilise material that is already failing underneath.
1. Inspect before choosing the preparation
Check for peeling and bubbling paint, bare timber, open joints, soft or rotten boards, mould or mildew staining and areas exposed to stronger sun or rain. Different elevations of the same Melbourne house can require different preparation.
2. Wash and remove contaminants
Dirt, chalking and biological growth reduce adhesion. Surfaces need to be clean and suitably dry before sanding, priming and coating.
3. Scrape and sand unstable paint
Loose paint should not simply be buried under another coat. Failed edges are normally scraped and feather-sanded so the new coating is applied to a sounder surface.
4. Deal with damaged timber
Minor surface defects may be part of normal painting preparation. Rotten or structurally damaged boards are different: replacement or repair can be required before painting.
5. Prime bare areas
Exposed timber and some repaired surfaces need an appropriate primer before finish coats. The product choice depends on substrate and coating system.
6. Work with Melbourne weather
Exterior work should allow for rain, surface moisture, temperature and drying time. Shaded elevations can stay damp longer than areas receiving direct sun.
How often should weatherboards be repainted?
There is no reliable fixed number for every house. Exposure, previous preparation, coating quality, timber condition and maintenance all affect repaint cycles. Early maintenance is usually less costly than waiting for widespread coating failure.
Local coverage: Painters across Northern Melbourne