Quick answer: Building exteriors should not all be washed the same way. Concrete and sound brick can handle moderate pressure. Stucco, painted siding, wood and older masonry need low pressure or “soft washing” with a gentle cleaning solution. Glass and window frames need low pressure and a spot-free rinse. The right method depends on the material, its age and its condition.
A clean facade changes how a building reads to tenants, buyers and visitors. But exterior cleaning done with the wrong pressure can strip paint, force water behind cladding or erode mortar joints, and those repairs cost far more than the cleaning itself. Here’s what commercial property owners should know before booking.
Pressure Washing vs. Soft Washing
Traditional power washing uses high pressure to blast dirt off a surface. Soft washing uses low pressure, closer to a strong garden hose, combined with a cleaning solution that loosens algae, mildew and grime so it rinses away. On many facades, soft washing is safer and the results last longer because it treats organic growth instead of just knocking off the top layer.
Surface-by-Surface Guide
Concrete and tilt-up panels
Concrete is the most forgiving exterior surface. Moderate pressure works well, and hot water helps with grease or exhaust staining near loading areas. Watch for joint sealant between panels, which can be damaged by a nozzle held too close.
Brick
Modern brick in good condition can usually be power washed at moderate pressure. Older brick and soft mortar are a different story. High pressure can erode mortar joints and open the face of the brick to water. A low-pressure wash with an appropriate cleaner is the safer default, especially on heritage or older buildings.
Stucco
Stucco is porous and can crack or gouge under high pressure. Water forced into cracks can also get behind the finish. Stucco should be soft washed, working from the bottom up to avoid streaking and rinsing from the top down.
Vinyl, fibre cement and painted siding
Siding is designed to shed water downward, not resist a jet aimed upward at the laps. Low pressure, a downward spray angle and a mild cleaner prevent water from getting behind the boards. On painted siding, too much pressure can lift paint, especially if it’s already aging.
Wood
Wood trim, soffits and feature walls should be cleaned gently. High pressure raises the grain and leaves a fuzzy, damaged surface that needs sanding and refinishing.
Glass, storefronts and window frames
Glass itself is durable, but seals and gaskets aren’t. Low pressure and a pure-water or spot-free rinse prevent streaks and protect seals. Storefront glass at ground level is usually cleaned as part of entrance maintenance.
Metal panels and awnings
Metal cladding and awnings collect traffic film and pollen. Low to moderate pressure with a mild cleaner works well. Avoid abrasive products that can scratch finishes.
Quick Reference Table
| Surface | Pressure | Notes |
|---|---|---|
| Concrete / tilt-up | Moderate | Protect panel joint sealant |
| Modern brick | Low to moderate | Check mortar condition first |
| Older or heritage brick | Low | Soft wash preferred |
| Stucco | Low | Soft wash; check for cracks |
| Siding | Low | Spray downward, never up into laps |
| Wood | Very low | Avoid raising the grain |
| Glass / frames | Low | Spot-free rinse; protect seals |
| Metal / awnings | Low to moderate | No abrasive products |
Before the Crew Arrives
- Inspect for damage. Cracks, loose sealant and failing paint should be noted so they aren’t made worse.
- Close windows and vents. Tenants and residents should get notice in advance.
- Protect landscaping. Plants near the wall may need to be wet down or covered.
- Cover electrical fixtures. Exterior outlets, lights and signage should be protected.
- Plan runoff. Wash water shouldn’t flow straight into storm drains.
How Often Should Building Exteriors Be Cleaned?
In Metro Vancouver’s damp climate, most commercial facades benefit from a cleaning every one to two years, with north-facing walls and shaded areas often needing more attention because algae and mildew grow faster there. Ground-level surfaces near entrances may need cleaning several times a year.
Frequently Asked Questions
Can power washing damage my building?
Yes, if the pressure or technique is wrong for the material. The most common damage includes eroded mortar, gouged stucco, stripped paint and water forced behind siding.
Is soft washing as effective as power washing?
For algae, mildew and organic staining, soft washing is often more effective because the cleaning solution treats the growth at the root instead of just removing what’s visible.
Do tenants need to leave during exterior washing?
No, but they should keep windows closed and may need to move patio furniture or vehicles parked against the building.
What about high-rise facades?
Upper floors of high-rises usually require rope access or lift equipment and are often handled as a separate specialized service. Ground-level and podium surfaces can be cleaned with standard equipment.
Protect Your Facade While You Clean It
EcoPlanet Property Services cleans building exteriors, entrances and walkways across Greater Vancouver with pressure matched to each surface and eco-friendly cleaning products. Request a free quote or call 604-565-5238 to book a walk-through.
