Walk around almost any older Melbourne home that is due for a repaint and the walls will look tired but intact. The windows are a different story. The sills are grey and split, the bottom rail of each sash has flaked back to bare timber, and the paint along the glass has cracked away in short lengths. That is not bad luck, and it is not usually a bad paint job either. Timber windows simply take more water and more sun than anything else on the front of the house, in the places where paint holds on worst. Knowing where and why they fail tells you what kind of repair the window actually needs.
Call Jimmy — 0432 077 782A wall sheds rain. A window frame catches it. The sill is built to throw water away from the house, but it does that by taking the water first, and every drip runs down the face of the sash and stops on the bottom rail before it reaches the sill. Those two horizontal pieces stay wet far longer than anything vertical around them.
The joints make it worse. Where the bottom rail meets the stiles, and where the sill meets the frame, there is end grain. End grain soaks up water the way a bundle of straws does, and once paint cracks over a joint, which it eventually will as the timber moves, water gets straight into the wood. Old putty along the glass behaves the same way: once it dries out and cracks, rain sits in the gap between the glass and the timber.
Timber moves with moisture and with heat. Windows on the north and west sides of a Melbourne house take the strongest afternoon sun, so the timber there swells and shrinks through a bigger range than the wall it sits in. Paint is a thin film stretched over that movement, and the film cracks first wherever the movement is greatest, which is across the joints and along the edges.
Colour matters here too. A dark frame absorbs far more heat than a pale one, so the timber under it runs hotter and moves more. That does not mean dark frames are a mistake, but on a sunny elevation they need sound timber, good preparation and a coating suited to it, or they show their age first.
Start at the bottom. Paint flaking off the bottom rail and the sill, with the upper parts of the frame still sound, is the common pattern and usually means water rather than a fault in the paint itself. Grey, weathered timber where the paint has gone means the wood has been exposed for a while and its surface fibres have broken down, so it needs sanding back to sound timber before anything will stick to it.
Then check whether the timber is still firm. Press a screwdriver into the sill and the lower corners of the sash. Firm timber resists. If the tip sinks in easily, or the wood is spongy and dark, that is rot, and paint will not fix it. Look along the glass as well: cracked or missing putty lets water in behind the paint and is often where rot starts.
A spot repair is the right call when the timber is sound and the failure is local. The loose paint is scraped back to a firm edge, the edges are sanded so the old paint feathers into the bare timber instead of leaving a step, bare wood is primed, cracked putty is replaced, and the joints are sealed before the topcoats go on. Done properly, a repaired sill sits in with the rest of the frame rather than standing out as a patch.
A full strip makes sense when the paint has failed across the whole window rather than in places: cracking in a fine crazed pattern all over, layers so thick the sashes no longer close properly, or old coatings lifting in sheets. In those cases, putting another coat on top only adds weight to a film that is already letting go. Stripping takes longer, and in a house built before 1970 the old layers should be treated as possibly containing lead and handled accordingly before anyone sands or heats them.
Rot is a separate decision. Small soft patches in otherwise sound timber can be cut back and filled with a filler made for exterior timber. Rot that runs deep into a sill or through a bottom rail is a joinery job: the piece is spliced or replaced first, and the painting comes after. Painting over rot to get a job finished only hides it for a season.
Windows have to open. Double-hung sashes painted shut, or painted so heavily that they bind, are one of the most common results of a rushed repaint. The sashes need to be freed and moved while the paint dries, and the edges that slide should not be built up with coat after coat.
The cheapest maintenance on any timber window is a look at the sills and bottom rails once a year. A crack over a joint caught early is a small touch-up. The same crack left for a few wet winters is new timber. If the walls still look fine but the windows are starting to go, it is often worth doing the windows on their own rather than waiting for the whole exterior.
Because the sill and the bottom rail of the sash are horizontal surfaces that catch and hold water, they take strong sun on the north and west sides, and their joints expose end grain that soaks up moisture once the paint over them cracks. Walls shed rain; window frames collect it.
It depends how far the rot goes. Small soft patches in otherwise firm timber can be cut back and filled with an exterior timber filler, then primed and painted. If the rot runs deep into the sill or through a bottom rail, that section needs splicing or replacing by a carpenter before it is painted, otherwise the paint is only covering the problem.
Not usually. If the timber is sound and the failure is limited to sills, rails and joints, scraping back to a firm edge, feathering, priming the bare timber and repainting is the right repair. A full strip is worth it when the paint has failed across the whole window or is so thick the sashes stick.
In Melbourne homes built before 1970 it is possible, and window frames are one of the most likely places to find it because they were often painted with oil-based gloss. Older layers should be treated as possibly lead-based until tested, and not dry-sanded or burnt off without the right precautions.