FOLLOW US
hello@happydogplumbing.london
0208 8797372

How To Safely Jet Wash Your Patio Without Damaging Your Pipes And Drains

When springtime starts to kick in, our natural urge to clean everything in sight also begins to flourish. For the ‘outdoorsy’ among us, this urge extends to jobs in the garden too. Jet washing the patio is often top of the list as we all dream about getting back in the garden again for those long-awaited family BBQs and alfresco gatherings with friends.

A powerful wash can strip away months of built-up dirt, moss, stains, and algae, leaving your patio and pathways looking brand new. However, if not done correctly, jet washing can lead to unexpected problems like blocked drains, pipe damage, and even unpleasant odours. To help you avoid these issues, we’ve put together essential tips on how to jet wash your patio safely, without causing plumbing headaches.

How Misusing A Jet Wash Can Damage A Patio Or Driveway

It is important to know how to jet wash a patio as using excessive water pressure, particularly on natural stone paving or porcelain outdoor tiles can cause unnecessary damage if not done mindfully, including:

  • Surface erosion and etching, particularly on natural stone. This not only makes paving prone to further damage, but it increases the speed at which it accumulates dirt as well. Softer types of sandstone are even more vulnerable to damage because of jet washing.
  • Damage to pointing. The pressure can often dislodge the joining material between the slabs or tiles. If disturbed, it compromises the stability of the patio and creates an uneven surface. Plus, it doesn’t look very aesthetically pleasing.
  • Chipping and cracking. This sometimes occurs at the slab edges, particularly if the material has weaknesses to begin with.
  • Fading and discolouration resulting in a patchy appearance.
  • Removal of sealant protection. Too much water force can wear away the protective layer which can leave it more susceptible to staining.

Why Jet Washing Can Cause Drainage Problems

Whilst jet washing is a great way to clean driveways, patios and other outdoor surfaces, it can also wreak havoc with your drains. While the high-pressure water removes stubborn dirt and grime, it can also create unintended damage on your drainage system in several ways:

High-Pressure Water Can Force Debris Into Drains

It is true that jet washing lifts dirt, moss, algae, and a number of stains from surfaces, but rather than disappearing, this debris often gets pushed directly into outdoor drains. Over time, this buildup can cause nuisance blockages, slowing down water flow and leading to standing water or even flooding. Leaves, gravel, and other particles loosened by the pressure wash can further contribute to the problem, making routine drain maintenance essential.

Potential
For Pipe
Damage

Older or weaker pipes aren’t built to withstand the force of high-pressure jet washing. Many of the properties we are called to in (and around) London have ageing drainage systems with older clay or cast-iron pipes which can be more fragile than modern PVC alternatives. The extreme pressure can crack, dislodge, or even break underground pipes, especially if they are already compromised by age or tree root intrusion. Damaged pipes can cause leaks, subsidence, and costly repairs, turning a simple cleaning job into a major issue.

Wastewater Can
Carry Chemicals
And Oils Into Drains

Many jet washing detergents contain chemicals that can accumulate inside drainage pipes. When mixed with grease, oils, and organic debris, these substances can create stubborn blockages or even contaminate nearby water sources. If wastewater isn’t properly managed, it can also lead to environmental concerns, as harmful substances can be washed into storm drains, impacting local ecosystems.

Risk Of Flooding
And Water
Pooling

When drains become clogged due to debris and sludge build-up, excess water has nowhere to go. This may lead to flooding on your property, water pooling in low-lying areas, and even damp issues in nearby buildings. Over time, poor drainage can weaken foundations and cause long-term structural problems.

How To Clean A Patio Or Driveway With A Jet Wash

Choose The Right Pressure Washer

In order to control the force of the water, select a pressure washer with an adjustable pressure setting. Look for a jet wash with an adjustable nozzle to help you control the angle of the spray.

We recommend using a medium-pressure setting to prevent unnecessary force on pipes and joints.

Keep the jet washer angled downward to avoid directing water straight into drain openings.

Clear The Area And Drains Before You Start

  • Remove any garden furniture, plants, toys, or ornaments that could be damaged while jet washing.
  • Remove loose debris, leaves, and moss manually.
  • Sweep the area thoroughly with a stiff-bristled broom.
  • Use a drain cover or filter to catch large particles before they enter the drain.

Wear Appropriate Safety Gear

Before you start, make sure you are appropriately dressed. Gloves, non-slip shoes and goggles are recommended to protect yourself from any debris or water spray. If it’s sunny, don’t forget the sun cream as depending on the size of your area, it can take a while!

Control The Water Flow

  • Work in sections and direct water toward the garden or drainage channels, not straight into the drains.
  • Use a brush to move excess water toward safe drainage areas.

If you are directing water onto your lawn, adjusting the angle of the jet washer to prevent excess runoff towards one spot can strategically direct the water flow. Aerating the lawn can also help improve drainage by allowing water to soak into the soil more effectively.

How To Aerate Your Lawn Effectively

  • Manual aeration: Use a garden fork or a manual aerator to poke holes about 2–4 inches deep and a few inches apart. Best for small areas.
  • Spike aeration: Uses solid spikes to create holes, but this can compact the soil around them instead of removing plugs.
  • Core/plug aeration: The best method—removes small plugs of soil, allowing better drainage and reducing compaction. Can be done with a core aerator machine or a manual coring tool.
  • Mow the grass shorter than usual.
  • Water the lawn a day before aerating to soften the soil (if it’s dry and compacted).
  • Mark any sprinkler heads or hidden cables to avoid damaging them.
  • If using a manual tool, push it into the soil and rock it slightly before pulling it out.
  • If using a machine aerator, go over the lawn in a consistent pattern, like mowing.
  • Focus on high-traffic or compacted areas more thoroughly.
  • Leave the soil plugs on the lawn; they will break down naturally and enrich the soil.
  • Apply compost, sand, or a top-dressing mix to improve drainage.
  • Overseed if necessary, and water the lawn well.
  • Avoid heavy foot traffic for a few weeks to let the soil settle.

Use Eco-Friendly Cleaning Solutions

Avoid harsh chemicals that can cause residue buildup in drains. Consider natural alternatives like vinegar and baking soda for stubborn stains.

Flush The Drains After Jet Washing To Prevent Odours And Blockages

After jet washing, flush outdoor drains with a bucket of clean water to clear any trapped debris. Dirt, algae, and moss can break down over time, leading to foul odours, especially if water pools in a partially blocked drain. Organic matter mixed with cleaning agents can also contribute to unpleasant smells.

To prevent this, use a drain cleaner or a mixture of boiling water and baking soda to clear minor blockages and neutralise odours. If the smell persists despite these efforts, it may indicate a more serious issue – consider calling a professional for further inspection.

WHAT’S THE PRESSURE WASHER FOR PATIO CLEANING? Check out Gardener’s World Pressure Washers Buyers Guide for an in-depth look.

When To Call A Professional Plumber

It’s time to enlist the help of a professional plumber if:

  • Water is draining slowly or backing up.
  • You hear gurgling sounds from your drains.
  • The foul smell doesn’t go away after cleaning.
  • You suspect external drain damage due to high-pressure washing.

Now that you are fully aware of the damage that jet washing can cause to your outside space and drains when not carried out efficiently, you’ll know how to pressure wash your prized patio safely to avoid costly repairs, bad smells, and blocked drains. In summary:

Key Steps to Jet Wash Your Patio Safely

  • Choose the Right Pressure Washer – Use a medium-pressure setting with an adjustable nozzle to control water force.
  • Prepare the Area – Remove furniture, sweep away debris, and cover drains to prevent blockages.
  • Wear Safety Gear – Protect yourself with gloves, goggles, and non-slip footwear.
  • Control Water Flow – Work in sections, direct water away from drains, and use a brush to manage excess water.
  • Use Eco-Friendly Cleaners – Avoid harsh chemicals that can clog pipes and harm the environment.
  • Flush Drains Afterwards – Rinse drains with clean water or a baking soda solution to prevent odours and blockages.
  • Call a Professional if Needed – If drains back up, smell bad, or show signs of damage, seek expert help.

If you are experiencing drainage problems and need the help of the team at Happy Dog Plumbing for professional drain maintenance or repairs, please don’t hesitate to contact us. We’d be happy to help.

Oliver Osmore has been at the helm of Happy Dog Plumbing since it became part of the Maintracts Services family, bringing with him decades of experience in plumbing, heating, and electrical services. As Managing Director of both companies, Oliver is dedicated to ensuring Happy Dog Plumbing continues its proud tradition of delivering exceptional service and innovative solutions to customers.

Oliver’s approachable nature and problem-solving expertise allow him to work closely with customers, offering tailored solutions to even the most complex challenges. He is passionate about upholding the high standards that Happy Dog Plumbing has become known for, ensuring every job is handled with professionalism and care.

Since its founding, Happy Dog Plumbing has been a trusted name in installation, maintenance, and repair services. Under Oliver’s leadership, the company thrives as part of a larger, customer-focused team, staying true to its roots while benefiting from the expanded resources of Maintracts Services. 

Powered by  GDPR Cookie Compliance
Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.