Painting a Weatherboard House: What It Really Involves

Weatherboard homes are still scattered right through Doncaster, Bulleen, Templestowe and Donvale, sitting between the brick veneer of the seventies and eighties and the newer builds. They are good houses. They also depend entirely on their paint, because on a weatherboard home the coating is not decoration, it is the waterproofing.

Brick can sit unpainted for a century. Timber cannot. That single difference explains why weatherboard repaints cost what they do and why cutting corners on one is such a poor economy.

Where weatherboard actually fails

Rot turns up in the same three places on nearly every house.

Board ends come first, particularly where boards run into corner stops or die against window and door reveals. End grain behaves like a bundle of straws: it draws water in and holds it. Paint fails at that joint, water gets in, and the board softens from the inside while the face still looks acceptable.

The lowest boards near ground level are next, because water splashing off paths, paving and garden beds keeps them damp. Anywhere the ground level has crept up over the years against the boards is worse again.

Then the weather-facing elevation. In Manningham that usually means the northern and western walls, which take the sun as well as the rain and where coatings chalk and fail first.

The quick test is a screwdriver. Press it into board ends, under window sills and along the bottom boards. If it sinks in, that is rot, and no amount of paint will address it.

Repair before painting

Soft sections get cut back to sound timber and spliced with matching profile boards. That is genuine carpentry and it takes time, which is why it shows up as a variable in quotes.

The alternative some contractors take is filling. Filler is fine for nail holes and small splits. It is useless for structural rot, because it has no strength and does nothing to stop the decay behind it. A filled rot pocket looks perfect on handover day and reappears in two or three years, taking the new coating with it.

Loose boards get re-fixed, splits are cleaned out and filled with a flexible compound that moves with the timber, and old coatings come back to a firm edge rather than being feathered over failing paint.

Lead paint on older homes

Australian domestic paint contained lead until the 1970s. On a pre-1970 weatherboard home, assume it is under there somewhere, usually beneath several later coats.

Intact lead paint is not the problem. Disturbing it is, and preparation disturbs it by definition. That means wet scraping rather than dry power sanding, drop sheets to capture debris, and controlled collection and disposal rather than letting chips fall into the garden.

This is slower and it costs more. A quote that is notably cheaper on an older weatherboard home is frequently cheaper precisely because this has been left out.

Priming matters more than the topcoat

Bare timber gets primed the same day it is exposed. Stripped weatherboard left open overnight picks up moisture and dew, and the primer then seals that in.

End grain at joints and cut ends needs particular attention, because that is exactly where water got in last time. An oil-based primer soaks into end grain in a way a water-based product does not.

Most people focus on the topcoat brand when comparing quotes. The primer and the preparation determine how long the job lasts far more than the topcoat does.

Coating choice

Weatherboard moves. It expands and contracts through a Melbourne year, and the coating has to move with it. A quality flexible exterior acrylic system handles that; a hard, brittle film cracks at the joints and lets water in.

Two topcoats over a properly primed surface is the standard. One heavy coat is not a substitute, because film thickness built in a single pass cures unevenly and sits soft.

How often will it need doing

A sheltered weatherboard elevation holds up for many years. A fully weather-exposed northern or western wall will always be due sooner.

It is completely reasonable to repaint the exposed elevation on a shorter cycle rather than doing the whole house every time. That approach keeps the protection intact where it matters and spreads the cost, and it is what we generally recommend to owners of older weatherboard homes around here. There is more on timing in our piece on how often you should repaint a house in Melbourne.

What moves the price

The variables that matter are how much rot repair is needed, whether lead-safe preparation applies, how much of the old coating is failing and has to come back, access and height, and how many separate elements are involved once eaves, fascias, windows and verandah timbers are counted.

Two quotes for the same weatherboard house can differ substantially and both be honest, because they are describing different amounts of work. The useful question is not the number but what happens if rot is found once the scraping starts, and whether that is priced or excluded.

Weatherboard work sits inside our Exterior House Repainting service, with roofline elements handled as part of Weatherboard, Eaves and Fascia Repaints. Where a home combines timber with rendered sections, Render and Masonry Painting covers the rest of the facade.

The short version

Check the board ends and the bottom boards before you do anything else. Splice rot rather than fill it. Treat anything pre-1970 as lead-painted. Prime bare timber the day it is opened up, especially the end grain. Use a flexible system and two topcoats. Then keep an eye on the weather-facing wall, because that is the one that will tell you when the next repaint is due.