Most early paint failures start with a dirty or chalky surface. Washing is one of the cheapest steps in a repaint and one of the most important. Here is what it does and how to do it without damaging the building.
Why washing comes first
New paint needs a clean, sound surface to bond to. Dirt, chalk from old paint, salt and mould all weaken that bond, which leads to peeling and early fading. Near the coast, salt left on a wall is one of the main reasons a repaint fails early. See why façade paint fails.
Right pressure for the surface
- Concrete paths and driveways usually take higher pressure
- Render, brick and painted walls need a gentler wash
- Timber, sealant and window seals are easily damaged and need care
- Mould is treated with a suitable cleaner, not just pressure
Timing before painting
Walls need to dry fully after washing. Washing is usually done at least a day before painting, longer in cool or shaded areas.
High walls and façades
Upper walls on apartment and commercial buildings can be washed by rope access pressure cleaning, working from the roof down, with water and debris controlled below. The same access is then used for repairs and painting, which keeps the cost of access down.
Cleaning as maintenance
Between repaints, a regular wash of entries, paths, car park ramps and bin areas keeps a building looking cared for and shows up defects early, such as cracks, rust stains and failed sealant. Many strata buildings add it to a planned maintenance program.
Common questions
Should walls be washed before repainting?
Yes. Paint does not bond well to dirt, chalk, salt or mould. Washing is a standard part of exterior preparation and is usually done a day or more before painting so surfaces can dry.
Is high pressure always best?
No. Render, timber, sealant and older paint can be damaged by too much pressure. The pressure and nozzle should suit the surface, and some areas are better cleaned with a lower-pressure wash and detergent.
How often should strata common areas be pressure cleaned?
Many buildings clean paths, entries and car park ramps once or twice a year, and walls less often. Shaded, damp areas that grow mould may need more frequent attention.
Need a building washed before painting? Request a quote or call 1300 926 176.
