Pressure Washing in Hong Kong Island

Common products are sodium hypochlorite (bleach) solutions for organic growth, degreasers for oil, and biocides for moss and algae. Used properly they are rinsed off and diluted, but they can harm plants, pets, and ponds during application. Ask the pro how they protect garden beds and where the runoff drains — dirty water should not go into surface-water drains in many jurisdictions.

Four things drive the spread: surface area and condition (heavy staining doubles the time), access (upper storeys, tight side passages), method (soft washing with chemicals costs more than a quick rinse), and what is bundled (resealing, weed treatment, gutter clear-out). A cheap quote is often just a rinse with no pre-treatment — clarify the scope before comparing numbers.

Move cars off the driveway, clear pots, furniture, and toys from the work area, close all windows and doors, and cover or flag anything fragile like garden lights. Point out hairline cracks, loose pointing, or flaking paint in advance — pros will work around known weak spots but cannot see them under grime.

Most pros charge either by the hour or by surface area. A single driveway or patio is typically a 1-3 hour job at the low end of a pro's minimum call-out, while a full house exterior wash costs several times more. Get the quote broken down by surface (driveway, walls, deck, roof) so you can drop items to fit your budget.

Generally no — external walls are common property managed by the owners' corporation or management company. Individual owners hire pressure cleaners for private areas: rooftops they own, village house exteriors, garden or podium areas, and car parking spaces.

October to February — the dry season. Cleaning during the humid months (especially the March-May damp season) gives the shortest-lived results because mould regrows within weeks on damp surfaces.