Pressure cleaning before painting: when and why
Most early paint failures start with a dirty or chalky surface. Here is what washing does and how to do it without damage.
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. Washing is one of the cheapest steps in a repaint and one of the most important.
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.
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.
How we can help
We pressure clean strata and commercial buildings across Sydney, either as part of a repaint or as a regular maintenance service. See pressure cleaning and surface preparation.
Related
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.