Pressure Washing in Sha Tin Wai

Yes. Too much pressure or the wrong nozzle can etch concrete, blast mortar out of brick joints, splinter timber decking, strip paint, and force water behind siding or render. Roof tiles are especially vulnerable. Ask the pro what PSI and nozzle they plan to use per surface, and whether they soft wash delicate areas.

High-pressure washing damages most roof coverings — it strips granules from asphalt shingles, cracks and dislodges tiles, and can force water under the covering. Roof cleaning should be done by soft washing or manual moss removal plus a biocide treatment. If a company proposes blasting your roof at full pressure, choose someone else.

It is one of the cheapest kerb-appeal upgrades before selling or renting out a property. Estate agents consistently list exterior cleaning among the highest return-on-cost pre-sale jobs because it changes first impressions for a few hundred, not a few thousand. It will not fix structural issues, but it makes photos and viewings noticeably better.

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.