Pressure washing guide
How to pressure wash a house exterior
Cleaning the exterior of a London property requires a different approach to a standard driveway clean. The materials, height access and mix of surface types on most houses mean the correct method varies surface by surface. This guide covers what to do and what to avoid.
A London house exterior accumulates pollution staining, biological growth and general grime at a faster rate than most UK properties. Traffic exhaust particles, construction dust, rainfall and biological growth from shaded areas all build up on brickwork, render, fascias, gutters and paths over time. Cleaning the exterior of a house properly makes a significant visual difference, but it requires a more considered approach than cleaning a driveway, because several surface types on a typical London house should not be exposed to high-pressure water at all.
Every 1 to 2
years is the recommended interval for cleaning a London house exterior to prevent permanent staining
Top to bottom
always work from the top of the building downwards so dirty water runs off cleaned surfaces
50 cm
minimum nozzle distance from brickwork to avoid eroding mortar joints and damaging the brick face
Know which surfaces on your house can handle pressure
Most London houses are a mix of materials, and the approach needs to change for each one. Identifying what you have before starting prevents damage that can be expensive to repair.
Can be pressure washed
Modern dense brickwork (with care) • Concrete paths and drives • Unevenness in block paving • Gutters and downpipes externally • Painted concrete or masonry walls (low pressure)
Should not be pressure washed
Roof tiles and slates • Render and pebble dash • Victorian brickwork and lime mortar • Wooden window frames and fascias • Window glass at close range • Around electrical fittings
Essential preparation before cleaning a house exterior
Close all windows and doors
Seal any gaps around windows and doors that could allow water ingress. Water forced under window seals is a common cause of interior dampness after exterior washing.
Cover or isolate outdoor electrics
Cover outdoor power sockets, light fittings and security cameras with plastic sheeting or tape before beginning. Never point a pressure washer directly at any electrical fitting.
Protect plants and soft landscaping
Wet adjacent plants and grass before starting. Cover any sensitive plants near the work area. If using a cleaning agent, contain any runoff to prevent it reaching planted areas.
Inspect the brickwork and mortar
Walk around the property and check for cracked mortar, spalled brickwork or any areas showing signs of water damage. These should be repaired before cleaning, not after.
How to clean a house exterior step by step
For most London houses, cleaning is best split into sections. Tackle each elevation separately to keep control of dirty water runoff and ensure no area is missed.
1. Apply cleaning solution
Apply a biodegradable algae and mould remover working from bottom to top of the elevation. This prevents streaking. Allow 5 to 10 minutes dwell time.
2. Rinse from top to bottom
Rinse from the highest reachable point downwards using a wide fan nozzle. Keep the lance at least 50 cm from the surface and at a 45-degree angle to the wall.
3. Work in sections
Clean one section or elevation fully before moving to the next. Overlapping passes prevent missed patches and the sweeping motion prevents streaking.
4. Final rinse and inspection
Complete with a thorough final rinse to remove any remaining product residue. Inspect from a distance for missed areas or remaining staining.
When a professional makes more sense than DIY
For most London houses, hiring a professional is the sensible choice. A typical London property has Victorian or Edwardian brickwork that should not be exposed to high pressure, render that requires soft washing, and height access that requires professional equipment to reach safely without scaffolding or ladders. The cost of professional exterior cleaning is consistently lower than the cost of repairing damage caused by incorrect DIY pressure washing.
Professional pressure washing London
Complete house exterior cleaning across London
Cloud Nine provides professional house exterior cleaning across all London boroughs. We assess each surface, use the correct method and pressure settings for every material, and handle brickwork, paths and external cleaning as a complete package. Contact us for a free quote.
Part of our guide
Pressure washing help and guidance
Everything you need to know about pressure washing for London homes and businesses, from surface types to costs and what to expect from a professional clean.
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