Before We Start
Boundary walls in Gauteng take a beating. Summer storms drive water and soil splash up the base, winter wind carries dust and soot, and shaded sections grow algae and black mould year after year. Most precast walls also have a textured finish that traps grime in a way a smooth surface doesn't.
That's why we never treat two walls the same way. The process below is the framework; the settings within it change for every property.
The Six Steps
Step 1: Surface Assessment
We walk the full length of the wall and note the panel age, finish, any cracks or loose capping, and what contamination is present — biological growth, road soot, rust, efflorescence, or paint. This decides the chemistry and the pressure range for the job.
Step 2: Protecting the Surroundings
Gate motors, intercoms, electric fence energisers, light fittings, and delicate planting are covered or pre-wetted. Vehicles are moved away from the work zone.
Step 3: Chemical Pre-Treatment
A biodegradable treatment is applied to the wall and left to dwell. For algae and mould it kills the organism at the root; for soot and road film it breaks the bond between grime and concrete. You can read more about the products we use in our biodegradable cleaning solutions.
Letting the chemistry work for the right amount of time means the wash phase needs far less pressure — which protects the concrete and gives a longer-lasting result.
Step 4: Controlled Pressure Washing
We wash from the top down so dirty water never runs over cleaned sections. Nozzle angle, distance, and pressure are set for the panel's condition — older, weathered panels get a wider fan and lower pressure. Panel joints and the base of the wall, where soil splash collects, get extra attention.
Step 5: Spot Treatment
Stubborn marks like rust streaks, efflorescence, or paint overspray are treated individually once the main wash shows what's left.
Step 6: Final Rinse and Walk-Through
The wall, paving, and surrounding areas are rinsed down, and we walk the wall with you before we leave to make sure you're happy with every panel.
How Long Does It Take?
| Wall Size | Typical Duration |
|---|---|
| Up to 50 m² | Half a day |
| 50–150 m² | One day |
| 150–500 m² | One to two days |
| 500+ m² (estates, commercial) | Scheduled in phases |
Heavily fouled walls may need longer dwell times or a second treatment pass, which we'll confirm during the assessment.
What You Need to Do
- Make sure we have access to an outside tap
- Move vehicles, bins, and pot plants away from the wall
- Keep pets indoors during the treatment and wash
- Let neighbours know if we'll be cleaning the outside face of a shared wall
We don't apply pre-treatment ahead of a heavy storm — rain dilutes the chemistry before it can work. If the forecast turns, we'll reschedule rather than deliver a half-result.
Frequently Asked Questions
Do you use my water?
Yes, we connect to an outside tap on the property. Our process is designed to be water-efficient: pre-treatment means less washing time, and less washing time means less water.
Will pressure washing damage my wall?
Not when it's done correctly. We set pressure, nozzle, and distance according to the panel's age and condition, and older walls get a gentler approach. Damage happens when one high setting is used on every surface.
Can you clean painted boundary walls?
Yes, but painted walls need a much lower pressure to avoid lifting the paint. Where paint is already flaking, we'll tell you upfront that washing will remove the loose material.
After the Clean
A freshly cleaned precast wall usually stays looking good for 12 to 24 months, depending on shade, nearby trees, and traffic. Walls that face south or sit under trees will need attention sooner. Find out more about our full precast wall cleaning service.
Ready to restore your boundary wall? Book a free assessment and we'll take it from there.