That combination is what decides how long a repaint lasts, and it is why the same paint can look fine for fifteen years on a sheltered southern wall and be chalking in six on the western elevation of the same house.
Why exterior paint fails early in Sydney
Almost always one of four things, and three of them are preventable.
- Preparation skipped. Painting over chalking, flaking or dirty surfaces means the new coat is bonded to a failing one
- Painting new render too early, which traps moisture and alkalinity behind the film and causes blistering and patchiness
- The wrong product for the exposure, particularly near the coast where salt needs a coating that sheds it
- Genuine end of life, which is normal. A quality exterior coating in Sydney generally wants redoing every seven to ten years, sooner on north and west elevations
Coastal exposure changes the specification
Anything within roughly five hundred metres of open surf is a genuine coastal environment, which takes in most of Bondi, Coogee, Maroubra, Manly, Freshwater, Collaroy, Narrabeen and Cronulla. Sheltered water around Botany Bay, the Georges River and the Harbour is milder but not negligible.
Salt settles on the wall, dissolves in humidity, soaks into the surface, then crystallises as the wall dries. Those crystals expand and push coatings apart from underneath. On top of that you have relentless UV.
For these walls we specify accordingly, we pay attention to the details people skip such as sealing parapet tops and getting a proper fall on window sills, and we recommend a freshwater hose down of the exposed elevations a couple of times a year. That last one sounds trivial and it genuinely extends the life of the coating.
Surfaces we paint
Different substrates want different systems, and treating them all the same is how a repaint fails in patches.
- Rendered and texture coated walls, our most common exterior job
- Face brick and painted brick
- Fibre cement, blueboard, weatherboard and cladding
- Hebel and other panel systems
- Eaves, fascias, soffits and barge boards
- Front fences, retaining walls and garden walls
- Garage doors, gutters and downpipes
Weather and timing
Exterior painting is weather dependent and anyone who tells you otherwise is about to do a poor job. Paint will not go on in rain, it should not go on if rain is due within a few hours of the final coat, and it should not go on in direct heat where the surface dries far faster than the film can level out.
Autumn and spring are ideal in Sydney. Winter works fine on the days it is dry, though cure times stretch out and overnight condensation becomes a factor. Mid summer is workable if you follow the shade around the building rather than fighting it.
We would rather push a day than put a coat on that will not last, and we will tell you when that happens rather than quietly pressing ahead.