What Melbourne's climate does to timber cladding
Melbourne gives paintwork cold, wet winters and hot, dry summers, often with sharp swings inside a single day. Timber responds by taking up moisture and swelling, then drying and shrinking. Every cycle works at the coating, opening hairline splits along board edges and around nail heads.
Sun exposure compounds it. North and west elevations lose gloss and colour first, and the coating chalks as the binder breaks down under UV. South-facing walls stay damp longer, so they are the ones that grow mould and lichen in the shaded corners.
Close to the bay — Williamstown, Port Melbourne and the streets behind them — wind-driven salt adds another load. Salt sits on the surface, holds moisture against the timber and accelerates corrosion of nails and fixings, which then bleed through the paint.
Preparation: the part that decides how long it lasts
On weatherboards, preparation is most of the job. A finish coat can only be as stable as what it sits on, so the sequence below is where we spend the majority of our time on site.
1. Protect and set up
Drop sheets, plant and window protection, and safe access set up before anything is touched.
2. Wash down
Sugar soap or a controlled wash to remove dirt, chalking, salt residue and mould so the new coating can bond.
3. Scrape
All loose and flaking paint scraped back to a sound edge, then feathered so the repair does not telegraph through.
4. Sand
Sanding to smooth ridges, feather edges and key the existing coating.
5. Fill
Minor defects — nail holes, small splits, open joints — filled with an appropriate exterior filler.
6. Prime bare timber
Every exposed section of bare timber sealed with a quality exterior timber primer, with particular attention to end grain, which drinks moisture.
7. Undercoat
Undercoat where required: over filler, over patchy primer and for significant colour changes.
8. Finish coats
Two premium exterior finish coats applied within the product's recommended conditions and recoat times.
Priming bare timber properly
On the period weatherboard homes common in suburbs like Yarraville, where timber may be a century old, this priming stage is where most premature repaint failures are prevented.
- Bare timber is sealed the same day where possible, so it does not take up moisture overnight.
- End grain, board ends and cut edges get extra attention — they absorb several times more moisture than the face of a board.
- Exposed nail heads and fixings are treated so rust does not bleed through the new coating.
- Knots and resinous areas are sealed appropriately to reduce bleed-through.
- Filler is only applied over primed or sound surfaces, then spot-primed before undercoat.
Product systems we use
We work with Dulux Weathershield and Haymes Solashield exterior systems. Both are premium exterior ranges formulated for Australian sun and weather exposure, with flexibility to handle timber movement.
The choice between them comes down to the substrate, the condition of the existing coating, the colour and the sheen you want. We match the primer and undercoat to the topcoat system rather than mixing and matching, and follow the manufacturer's spread rates and recoat times.
- Dulux Weathershield exterior systems over correctly primed timber.
- Haymes Solashield exterior systems where the job suits that range.
- Matched exterior timber primers and undercoats — never a topcoat straight onto bare timber.
- Appropriate exterior fillers and flexible sealants at joints and gaps.
Signs your weatherboards are due
- Chalky residue on your hand when you rub the surface.
- Hairline cracking or flaking along board edges and around nail heads.
- Bare grey timber showing through on the sunny elevations.
- Paint lifting in sheets near gutters, downpipes or garden beds — usually a moisture source, not a paint failure.
- Mould or lichen on shaded southern walls that keeps coming back.