Pressure washing guide
How to use a jet wash
A jet wash is one of the most effective outdoor cleaning tools there is. From patios and driveways to cars, fences and garden furniture, it can transform surfaces in a fraction of the time of manual scrubbing. This guide covers everything you need to use one safely and effectively.
A jet wash, also called a pressure washer or power washer, uses a pump to force water through a lance and nozzle at high pressure, using the kinetic energy of the water to blast away dirt, algae, moss, grime and staining from outdoor surfaces. It is one of the most versatile and satisfying outdoor cleaning tools available, cutting cleaning times dramatically compared to manual scrubbing. Understanding how to set one up, choose the right nozzle and match the pressure to the surface makes the difference between excellent results and surface damage.
Start low
always start on the lowest pressure setting and increase gradually (easier to prevent damage than repair it)
30 cm
minimum nozzle distance from most surfaces, closer concentrates pressure and risks damage to paving and paintwork
Top to bottom
always work from the top of any surface downwards so dirty water runs off cleaned areas ahead of you
How to set up a jet wash
1. Connect the water supply
Connect the garden hose to the water inlet on the machine. Ensure the hose is long enough to reach your work area without stretching. Turn on the water supply at the tap.
2. Purge air from the system
Before switching on the power, squeeze the trigger on the lance with the machine off. This floods the system with water and purges any air, preventing pump damage. Once water flows cleanly from the lance, the machine is ready to start.
3. Select your nozzle
Attach the appropriate nozzle for the surface you are cleaning before turning on the power. Never change nozzles while the machine is running. An incorrectly seated nozzle can be ejected at high velocity when pressure is applied.
4. Test in an inconspicuous area
Always test on a small hidden area first at the lowest pressure setting. Check the surface reacts well before cleaning the full area. Increase pressure gradually only if the result is not sufficient.
Understanding jet wash nozzles
Nozzles control both the spray angle and the effective pressure at the surface. A narrower angle concentrates the pressure on a smaller area, increasing cleaning power but also increasing the risk of surface damage. Most pressure washers use colour-coded nozzles.
Quick reference by surfacePressure settings for common surfaces
Concrete and stone patios
Green nozzle (25°), medium to high pressure, 30 to 50 cm distance. Surface cleaner attachment recommended for large areas.
Block paving driveways
Green nozzle (25°), medium pressure, diagonal to joints. Re-sand joints after every clean.
Natural stone (sandstone, limestone)
White nozzle (40°), low pressure, 50 cm+. Never use vinegar or acid cleaners on these surfaces.
Decking
White nozzle (40°), low pressure, along the wood grain only. Never use a pencil jet on wood.
Car bodywork
White nozzle (40°), 1,200 to 1,900 PSI, 30 cm minimum. Never exceed 2,000 PSI on paintwork.
House exterior brickwork
White nozzle (40°), medium pressure, 50 cm minimum from wall. Never use on lime mortar or Victorian brick.
Jet wash safety essentials
A jet wash produces a water stream capable of breaking skin at close range. Always wear safety goggles, waterproof footwear and sturdy gloves. Never point the nozzle at people, animals or pets. Never use a jet wash while standing on a ladder — the reaction force can cause loss of balance. Keep children well clear of the work area at all times. Always point the nozzle at the ground before pulling the trigger after changing nozzles or restarting — the initial burst is often stronger than the set pressure.
Professional pressure washing London
Professional jet washing across London by Cloud Nine
Cloud Nine provides professional pressure washing across London for driveways, patios, house exteriors, vehicles and commercial premises. We bring the right equipment for every surface type and deliver results that last. Contact us for a free quote.
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Pressure washing help and guidance
Everything you need to know about pressure washing for London homes and businesses.
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