Pressure Washing in Northern Ireland

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.

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.

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.

Renting a machine costs a fraction of a pro visit, but consumer machines are slower, and the main risks are damage (etched concrete, stripped paint) and injury — a 3000+ PSI jet can cut skin. DIY makes sense for a small, flat concrete area. Hire a pro for two-storey walls, roofs, timber, render, or anything needing ladders or chemicals.

Most residential pros use your outdoor tap and, for electric machines, an outdoor socket. Petrol-powered machines only need water. Some companies carry water tanks for properties without an accessible tap — ask in advance, as tank supply can add to the price. Water usage for a typical driveway job is modest, roughly comparable to a few loads of laundry per hour of cleaning.

UK guides put driveway cleaning at roughly £8.50-£15.50 per m². A single-car drive (up to 20m²) can be £40-£100, a standard two-car drive £100-£250, and large drives £250-£500. Resealing after cleaning adds £100-£200 to a medium drive.

Yes, but the jointing sand gets blasted out along with the grime, so the job is only complete once the joints are re-sanded (kiln-dried sand) and ideally sealed. If a quote doesn't mention re-sanding, the paving will loosen and weeds will return faster.