Patio Cleaner vs Pressure Washing: Which Is Better?
Both methods can improve the look of your patio, but they work in very different ways. A pressure washer (or jet wash) gives a fast surface clean, while a chemical cleaner penetrates the surface for a deeper, longer-lasting result.
Quick Comparison
Pressure washer / jet wash
Ideal for blasting away heavy mud, loose debris and general dirt. It delivers instant visual improvement,
but mainly treats what you can see on top. Because it doesn’t deal with the underlying growth,
regrowth of algae, moss and black spots is common.
Chemical patio cleaner
Works by breaking down and killing the organisms causing the staining, then loosening the dirt so it can be rinsed away.
This gives more of a deep clean into the pores of the stone, so results usually last longer
than pressure washing alone.
When Pressure Washing Works Best
Use a pressure washer when you need a quick tidy-up: thick mud, loose debris, sand and surface grime before an event or visit. It’s effective for an immediate makeover, but you should be careful on older or delicate surfaces to avoid damage to joints and stone.
When a Chemical Cleaner Is Better
A chemical patio cleaner is the better choice for stubborn black spots, green algae, moss and ingrained dirt, especially on more delicate or porous materials. Instead of just moving the dirt around, it targets the cause of the staining so the surface stays cleaner for longer and regrowth is reduced.
The Best of Both Worlds
For many patios, the ideal approach is to combine both methods: apply a chemical cleaner first to treat the growth and loosen the soiling, then follow up with a gentle rinse or light jet wash. This way you get the speed of a surface clean with the lasting benefits of a true deep clean.
Why Pressure Washing Can Make Problems Worse
It may sound surprising, but pressure washing can actually cause patio problems to return faster. High-powered water doesn’t just remove dirt — it can increase the stone’s porosity by opening up tiny pores and hairline cracks in the surface.
This makes the surface more porous and creates new anchor points where algae, moss, and lichen can attach and begin growing again. In other words, you may clean your patio today only to see problems regrow through normal recolonization weeks later.
Another issue is that jet washing removes what you can see, but often leaves roots or spores embedded inside the stone. There’s also the “protective biofilm” paradox: mature growth can form a weak shield over the stone. Strip it away aggressively and you expose raw material underneath, increasing the risk of surface damage.
A better approach is to treat growth properly with a patio cleaner, then use gentle rinsing rather than high-pressure blasting.
Why Choose Spray & Leave Patio Cleaner?
A spray and leave patio cleaner is all about convenience. You simply apply it to the surface and walk away – there’s no scrubbing, no jet washing and no need to keep rinsing. The product does the hard work for you.
After application, the treatment soaks into the surface and keeps working over time. Each time it rains, the formula reactivates with rain, helping to break down green growth and staining gradually. This creates a level of residual protection, so your patio stays cleaner for longer compared with one-off, aggressive cleaning.
Here’s how spray-and-leave compares with more traditional approaches:
Spray & Leave Cleaner
Effort: Very low – apply and leave in place.
How it works: Slow action with natural reactivation over weeks.
Results: Gradual but long-lasting, with reduced regrowth.
Pressure Washer / Jet Wash
Effort: High – set up, control and move the lance.
How it works: Blasts the surface for a fast clean.
Results: Instant improvement, but regrowth often returns quickly.
Traditional Scrubbing
Effort: Very high – manual brushing and rinsing.
How it works: Physically scrubs dirt from the top layer.
Results: Short-term tidy-up, limited lasting effect.
How Patio Guard Compares to Other Products
Not all patio cleaners work the same way. Understanding the results timeline, safety level, and method of action helps you choose the right product for your surface and situation. Here’s how Patio Guard compares with typical spray-and-leave products and acid-based cleaners.
🌟 Patio Guard: Performance & Safety
| Feature | Details |
|---|---|
| Results Timeline | Gradual improvement (over days/weeks) |
| Pressure Washer Needed | No (gentle rinse optional) |
| Pet / Child Safe | Yes (when used as directed) |
| Plant Safe | Use with care (avoid overspray) |
| Natural Stone Safe | Yes (including sandstone and concrete) |
💧 Typical Spray & Leave Cleaner
| Feature | Details |
|---|---|
| Results Timeline | Gradual, often less targeted |
| Pressure Washer Needed | Usually Not Required |
| Pet / Child Safe | Varies widely between brands |
| Plant Safe | Depends on formulation and dilution |
| Natural Stone Safe | Generally safe, guidance often unclear |
⚠️ Acid-Based Cleaner
| Feature | Details |
|---|---|
| Results Timeline | Fast (visible in minutes) |
| Pressure Washer Needed | Often Recommended After Use |
| Pet / Child Safe | Usually more hazardous to handle |
| Plant Safe | Higher risk of damage if splashed |
| Natural Stone Safe | Can damage limestone and sensitive stone |
Where Patio Guard excels: you get controlled cleaning with lower risk. It won’t give “instant” results in minutes like an acid, but it offers a safer, longer-lasting solution that doesn’t rely on force or harsh chemistry.
Patio Guard is the better choice if you value safety, surface protection and results that last — not just a quick cosmetic fix.
Why Patio Guard is the UK's Best Spray & Leave Cleaner
Patio Guard stands out because it’s designed to clean properly without relying on force or harsh chemistry. It combines long-working biocidal action with surfactants that lift ingrained grime, giving you lasting results instead of a quick cosmetic clean.
Safety is built into the formula. Patio Guard is pH neutral, non-caustic and uses biodegradable ingredients where possible. When used as directed, it is pet safe, plant safe and child safe once dry — making it suitable for everyday family homes, not just trade use.
You’re also buying from a UK-based business that specialises in exterior cleaning solutions, with technical support, clear usage guidance and customer service you can reach if you need help.
Each purchase includes a ready-to-use spray-and-leave solution, full instructions, and coverage designed to treat large patio areas efficiently — no extra equipment needed.
How to Use Patio Guard
Using Patio Guard is straightforward, but a few simple steps will give you the best results and avoid mistakes. Always read the label before use and check the coverage guidance for your patio size.
Application Steps
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Prepare the area
Clear furniture, pots and obstacles, then sweep away loose dirt, leaves and debris. This allows the product to reach the surface properly instead of sitting on top of muck. -
Apply with a garden sprayer
Fill a clean garden sprayer with Patio Guard and spray evenly over the surface. Aim for “wet but not pooling” – fully dampened stone without puddles forming. -
Leave to work – no scrubbing, no rinsing
This is a true spray-and-leave product. The dwell time is crucial: leave Patio Guard on the surface to dry and get to work over the following days and weeks.
Weather, Lawns & Second Applications
Apply in dry conditions, ideally between 10–20 °C, with no heavy rain forecast for a few hours. Avoid spraying directly onto lawns and delicate plants; lightly cover borders where possible. If grass at the edges is affected, it may discolour but should usually recover as it grows out.
Heavily soiled or long-neglected patios may need a second application after the first has had time to work. Allow several weeks between treatments so you can see the full effect before deciding if another coat is needed.
The Importance of Dwell Time
Dwell time (also called contact time) simply means how long the product is left on the surface to work. With Patio Guard, the cleaner must remain wet on the stone long enough for the ingredients to soak in and begin doing their job.
This matters for three reasons. First, the liquid needs time to penetrate into porous stone rather than just sitting on top. Second, it must reach the roots of algae, moss and lichen, not just the visible growth. Third, the active ingredients need time for full activation so the cleaning and treatment process can complete properly.
The most common mistake is applying a product and immediately rinsing it away. That stops it working before it’s had a chance to do anything useful.
With true spray-and-leave products, results happen over weeks, not minutes. Leave the surface alone and allow rain and weather to continue reactivating the treatment over time.
Best Weather Conditions for Application
For the best results, apply Patio Guard when the temperature is between 10–20 °C. This range allows the active ingredients to work properly without drying too quickly or reacting too slowly.
If it’s too cold, the chemical process slows down and results may take much longer to appear. If it’s too hot, the liquid can evaporate before it has time to soak in and work effectively.
Choose a period of dry weather with at least 12–24 hours of rain-free conditions after application. An overcast day is ideal, as strong sun can cause the product to dry too quickly on the surface.
In the UK, the best months for treatment are typically April and September, when temperatures are moderate and rainfall is lighter.
Avoid application during frost risk, extreme heat, or just before heavy rain.
See our complete seasonal patio maintenance calendar
Results You Can Expect
Spray-and-leave cleaners work in a gradual, progressive way. You won’t get instant “all-in-one” transformation in minutes, but you will see steady, long-lasting visible results over a period of weeks as the treatment takes full effect.
Week 1: First signs of change. Green algae begins to lighten and dry out, the surface looks less slick and
patches of improvement start to appear.
Week 2: More significant visible change. Large areas of algae and general soiling fade, and the patio starts
to look noticeably cleaner overall.
Week 3: The full effect develops. Stubborn staining continues to break down and the patio reaches its
best post-treatment appearance.
Severe cases: Very heavy growth, old black spots or long-neglected patios can take up to 3 weeks to reach
their maximum improvement.
The speed of results depends on factors like the level of soiling, stone type, porosity, temperature, shade and how evenly the product was applied. If, after 3 weeks, heavily soiled areas are still noticeably affected, a second application can help speed up the final result.
What Our Customers Say
Real patios, real timelines, and real results. Here are some examples of what customers typically report after using a spray-and-leave treatment like Patio Guard:
“20-year-old sandstone finally looks clean again.”
Emma, Leeds – “Our 40 m² sandstone patio had gone almost completely green. We’d jet washed it every spring but it
kept coming back. With Patio Guard, the first visible results showed after about 10 days, and by week 2 the green
algae had almost completely gone. By week 3 it looked better than after jet washing, and we didn’t lift a brush.”
“Black spots started to fade after years of frustration.”
Mark, Kent – “I’d tried two different ‘patio cleaners’ and a pressure washer on our block paving with no luck on the black
spots. After one application, I saw the lichen start to lighten over 2 weeks. By week 3 the worst spots had faded right
back and the rest of the paving looked much brighter.”
“Perfect for a busy family garden.”
Sarah, Glasgow – “We’ve got kids and a dog, so I wanted something easy and low effort. I sprayed it on one Saturday in
April and left it alone. Over the next few days the slippery green film disappeared from the steps and the patio. No
scrubbing, no pressure washer – just a steady improvement every time we looked.”
Patio Guard Product Details
Here’s everything you need to know before ordering Patio Guard, with clear, practical information so you know exactly what you’re buying.
Technical Specifications
Formula type: Spray & Leave patio cleaner
pH level: pH neutral
Safety: Non-caustic & biodegradable ingredients where possible
Use: External hard surfaces only
Coverage
Typical coverage: up to 20–25 m² per litre depending on surface porosity and level of soiling.
Rough or very absorbent stone may need more product than smooth surfaces.
Storage & Shelf Life
Store in a cool, frost-free place out of direct sunlight. Keep container sealed when not in use. Shelf life is typically 12–24 months when stored correctly.
What’s Included
Ready-to-use Patio Guard solution with clear instructions for application and coverage guidance.
Pricing & Bundles
Available in single 5ltr bottles with buy one get one free and free shipping included, perfect for larger patios or repeat treatment.
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Suitable for all surfaces
Patio-Guard patio cleaner is non caustic and works using a unique surfactant technology allowing it to be used on all surface types.
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Fast results
Patio-Guard gets to work immediately. After application, it degrades dirt and algae and removes them by breaking the debris down into micro-soluble particles, which then naturally wash away with rainwater.
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Easy Application
Patio-Guard is provides you with effortless cleaning. with our spray & walk away formula - no scrubbing or pressure washing is required, saving you time and effort.
Frequently Asked Questions
Is patio cleaner safe for pets?
Yes, patio cleaner is generally safe for pets once the surface is fully dry, typically after 2–4 hours in good conditions. Keep pets off the treated area while it is wet so they don’t walk through the solution. As the product dries, the active ingredients bind to the stone surface and do not transfer easily to paws.
Is patio cleaner safe for plants?
Patio cleaner is usually safe for established plants in adjacent beds when used carefully. Avoid direct spray onto leaves and delicate foliage. If overspray occurs, rinse plants with clean water as soon as possible. Once diluted by rain and weathering, most formulations are designed to be biodegradable.
Will patio cleaner damage my lawn?
If patio cleaner runs off onto an adjacent lawn, the grass may temporarily lighten or yellow at the edges. This is usually superficial and most lawns recover within 1–2 weeks as new growth comes through. Apply on calm days, avoid over-application near lawn edges and try not to let the product pool on the grass.
How long should I leave patio cleaner on?
For spray-and-leave products, dwell time is measured in weeks, not minutes. You apply and leave the cleaner in place so it can penetrate and work gradually – there is no need to rinse. Rain helps to reactivate the treatment over time. Avoid hosing or pressure washing the area for at least 7 days so the product can stay in contact with the surface.
What temperature should I apply patio cleaner?
The ideal temperature range for application is around 10–20 °C. Below 10 °C the reaction slows down and results may take much longer to appear. Above roughly 24 °C, the liquid can evaporate too quickly to soak in properly. Avoid using patio cleaner in frost conditions or during extreme heat.
Why isn’t my patio cleaner working?
The most common reason a patio cleaner seems not working is insufficient dwell time – applying and then rinsing off too soon. Other factors include applying in poor conditions (too cold, heavy rain soon after), very heavy contamination that simply needs a second application, or products that are biocides only, which kill growth but don’t actually clean the surface. If you have followed the instructions, waited several weeks and still see no change, contact support for advice.
What if it doesn’t work first time?
On heavily soiled patios, especially those not cleaned for 5+ years, it’s normal to need a second application. Allow 6–8 weeks for the first treatment to reach its full effect, then reapply to the remaining problem areas. Deeply embedded lichen and long-standing black spots often need two rounds of treatment to fade significantly.
Can I use patio cleaner on wood decking?
Some patio cleaners can be used on wood decking, but not all. Always check the product label first. Wood may require a different concentration and more careful application to avoid over-wetting. If you’re unsure, follow guidance specific to decking or use a cleaner formulated for timber surfaces.
What are the white marks on my patio?
Those chalky white marks are often efflorescence – mineral salts coming to the surface, not algae or lichen. Efflorescence forms when water carries dissolved salts through the stone and leaves them behind as it evaporates. It needs a different treatment to organic growth and often reduces naturally over time with rain and weathering.
Should I seal my patio after cleaning?
Sealing your patio after cleaning is optional but can be very beneficial. A good sealer reduces porosity, making future colonisation by algae and dirt more difficult and cleaning easier. Always wait until the patio is completely dry before sealing. If you’re interested, look for a dedicated guide on choosing and applying patio sealer.
How much patio cleaner do I need?
To estimate how much you need, first measure your patio (length × width) to get the area in square metres. Then compare that to the product’s coverage rate – for example, if 5 L covers around 25 m², a 50 m² patio would need about 10 L. It’s sensible to have slightly more than the minimum so you can apply evenly and treat stubborn areas twice if needed.