How To Clean Patio Pavers in Most Effective Way

In the moist climate of Ireland, greenery and filth can accumulate on the surface of the garden pavers and invade the joints.

As pavers are exposed to extreme weather and different conditions, cleaning them can be neglected until the accumulation of grime, greenery, and mess becomes unsightly. 

Or the dullness and green hues have made the pavers look tired. Learning about the processes of getting patio pavers clean can improve the look and feel of your outdoor living areas. 

Before You Start, Identify Your Pavers

This step gets skipped more than it should. In practice, the material a paver is made from changes what it can safely take. 

Where most cleaning damage actually comes from is choosing the wrong cleaning method or product. Clay pavers are fired at high temperatures and tend to be fairly dense. The surface finish and any coating still need to be considered before choosing a cleaner. 

Limestone and sandstone are both porous natural stones. This means they can absorb liquids, including cleaning products, more readily than a manufactured paver would. That porosity needs to be accounted for, especially with anything acidic.

At Royale Stones, our paving experts recommend that “before cleaning stone it is first vital to identify the type of stone it is.” 

Precaution: If there's any doubt about the exact material, checking with whoever supplied or installed the pavers is worth the five minutes it takes, because guessing wrong here is expensive to undo.

What You Need To Clean External Pavers

Start with these basics, then choose a cleaning approach based on your paver material. Below are the tools and accessories that you may require for cleaning patio pavers.

• Broom.
• Stiff-bristled outdoor brush.
• Bucket.
• Garden hose.
• A cleaner suited to the specific paver material.
• Gloves.
• Eye protection where the product label calls for it.
• A pressure washer, if one is available and appropriate for the material.

A pressure washer is useful but not essential. Outdoor pavers are remarkably easy to refresh; a stiff brush, a suitable cleaner, and a little patience are often enough to bring their natural character back to the surface. 

How To Clean Outdoor Pavers Step by Step

1. Clear the Area: Move furniture, pots, and anything else sitting on the pavers so nothing gets missed and nothing gets knocked over mid-clean.
2. Sweep the Surface: Do this before any water goes down to stop loose grit from turning into mud that gets ground into the surface once it's wet.
3. Remove Weeds & Moss: Pull or scrape this out by hand or with a joint tool before cleaning the surface itself. Removing them first allows you to clean the dirt and staining underneath properly. 
4. Check the Surface: Look for existing sealers, coatings, heavy staining or damaged areas before choosing how aggressively to clean.
5. Pre-Wet the Surface: Some cleaners work better on a damp surface; others need it dry. Follow the label rather than guessing.
6. Apply the Right Cleaner: A product that works well on concrete isn't automatically safe on limestone, so match the cleaner to the paver rather than to whatever happens to be under the sink.
7. Scrub the Surface: A stiff outdoor brush covers most jobs. Save harder bristles for stubborn patches rather than the whole area, since scrubbing everything at full effort tends to wear the surface unevenly.
8. Rinse Thoroughly: Leftover cleaner residue can leave the surface hazy or, worse, slippery once it dries, so rinse until the water runs clear. Realistically,
9. Inspect the Joints: In practice, cleaning, especially with a pressure washer, can loosen or wash out jointing material. That said, catching this now is easier than dealing with it after a few weeks of rain has made it worse.
10. Let the Pavers Dry: In practice, staining and discoloration are far easier to judge accurately once the surface has dried out properly, since wet pavers tend to look uniformly darker than they'll end up.
11. Treat Remaining Stains: Realistically, if a stain or patch of growth survives the first pass, the next move depends on what it actually is rather than reaching straight for a stronger product.

Can You Pressure Wash External Pavers

The answer sits between always and never. Pressure washing earns its place on heavy surface dirt, established algae, and general grime that a brush alone struggles to shift. 

Where it starts causing problems is at close range and with high pressure on porous natural stone like limestone or sandstone, or anywhere the jointing material is already loose. 

The pressure that lifts dirt off a concrete paver without issue can etch or pit a softer stone. It can blast jointing sand straight out of the joints in seconds, which then needs replacing.

Keeping the nozzle further back, working at a lower setting, and testing on a small, less visible area first covers most of the risk. 

Manual cleaning is worth considering as the starting point on any natural stone paver, or anywhere the growth is light rather than deeply embedded, since it gives more control over exactly how much force actually reaches the surface.

Removing Moss, Algae and Other Common Problems

Not every mark on an outdoor paver needs the same treatment. From moss and algae to oil, grease and everyday grime, each type of build-up needs a slightly different approach. 

Moss

It settles in wet, shady joints and works its way across the surface, and is often seen under a tree or on a north wall before anywhere else. Usually pulled or scraped out, treated and rinsed away. Tends to return wherever persistent dampness and shade remain, so rarely a permanent solution.

Algae and Green Growth

Green staining is almost always moisture left on the surface for too long. A cleaner suited to the paver material and good scrubbing action will usually remove it, but the amount of effort needed depends on how long it's been present.

Lichen

Tougher than most dirt, lichen usually needs a firm scrub or a longer dwell time with the cleaner than you would normally use for moss or algae.

Weeds

Weeds through the joints are more of a joint problem than a cleaning problem. Pulling them out by the root, not just cutting back above the surface, means they're less likely to return through the same gap in weeks.

General Dirt and Grime

Foot traffic and dust leave general dirt and grime that are best dealt with by a simple sweep, wash and scrub action.

Oil and Grease

While oil and grease will stain any paver, it's trickier to remove from porous stone than a sealed or manufactured paver. Degreasing suited to the material, used as soon as possible after the spill, offers the best chance of removing it.

Organic Stains

Leaves, bird droppings and spills of food or drink can all create organic stains on pavers that darken with age rather than fade. The sooner you treat them with mild soapy water, the lighter they're likely to be after cleaning.

Cleaning Clay, Limestone and Sandstone Pavers

Clay, limestone and sandstone each respond differently to cleaning, while other paver materials bring their own considerations around durability, porosity and surface finish. Here’s what to keep in mind for each type:

1. Clay pavers

Well-fired clay pavers tend to cope well with routine cleaning because their firing process creates a fairly dense, durable surface. 

Surface dirt, moss growing between the pavers and general algae tend to present the most common concerns. 

Efflorescence can appear as a pale, powdery surface deposit when moisture brings salts to the surface. It needs different treatment from ordinary dirt or algae.

A suitable Grimex intensive cleaner and a stiff brush usually tackle things quite effectively, and pressure washing will generally prove a safe option as long as pressure is kept to moderate levels and any coating or finish on the paver is taken into consideration. 

Checking the joints for any displaced jointing sand once the surface is clean is still as important to clay as any other type of paver.

2. Limestone Pavers

With their natural appearance and porous surface, limestone pavers bring plenty of character to an outdoor space, but that same porosity means they need a little more care when it comes to cleaning.

Acidic cleaners, which would be perfectly safe to use on concrete or even porcelain, may lead to etching or discolouration of the surface.

Limestone is sensitive to acidic products, which can etch the surface. Its porous nature also means liquids can absorb into the stone if left sitting too long.  

Checking for compatibility before actually applying a cleaner is always a good idea in this case. 

3. Sandstone Pavers

Like limestone, sandstone has a naturally porous surface, and sandstone pavers bring plenty of character to outdoor spaces, although their porosity means stains can sometimes penetrate deeper into the material.

Sandstone varies in porosity, so some pavers can absorb stains more deeply than others. Oil and grease may therefore need more than surface cleaning to remove fully.  

It is not difficult to clean but simply requires slightly more patience than other materials when it comes to choosing the appropriate product and approach. 

A suitable Solvex intensive cleaner, moderate pressure and patience will generally see sandstone pavers back to their former glory without having to risk the surface integrity.

4. Cleaning Other Garden Pavers

Concrete pavers tend to be fairly resistant to any cleaning process, including pressure washing, but excessive pressure will eventually have an effect either on the surface or the integrity of the joints. 

Porcelain pavers are dense and largely non-porous. This makes removing surface dirt and residue relatively simple as long as the product is given time to work rather than simply being dabbed on and left to dry. 

Granite pavers are hard-wearing, and cleaning them usually boils down to finding the right product for the specific finish rather than having to worry about the porosity as much as other materials require.

Common Mistakes That Can Damage Outdoor Pavers

• Turning the pressure washer up to maximum instead of working out what the pavers actually need.
• Not following the recommended dilution and dwell time, instead assuming a stronger mix will work faster.
• Treating every paver the same regardless of what it's made from.
• Skipping a test patch before using an unfamiliar product across the whole area.
• Leaving cleaner residue on the surface instead of rinsing it off properly.
• Leaving objects in place and missing areas where moisture and organic debris collect. 
• Letting damp, shaded conditions go unaddressed, so moss and algae just come straight back.
• Reaching for the strongest available method before trying something gentler first.

Final Words

Start with the least aggressive method that suits the condition and the material of the patio paver blocks; work out what the surface is made from before reaching for a cleaner, and take care around the joints. 

Use a pressure washer only where the paver can actually handle it and at a sensible setting. Regular sweeping and prompt attention to moss, leaves, and standing water do more for keeping pavers looking right than any single deep clean ever will.

For broader advice on looking after outdoor paving, our guide on how to clean and maintain garden paving slabs covers ongoing cleaning and maintenance.

FAQs

Q1. Can you pressure wash outdoor paver stones?

It depends on the type of paver. Concrete and clay pavers generally respond well to pressure washing, although it is important to avoid using too high a pressure setting. On limestone and sandstone, a gentler, broader jet is advised to avoid surface marking and dislodging the jointing sand.

Q2. How do you clean external paving stones without a pressure washer?

Sweep the pavers and remove weeds and moss from the joints, treat the surface with an appropriate cleaner, agitate with a stiff brush, then rinse well. It takes longer than using a pressure washer, but is a perfectly viable method of cleaning for moderate dirt and/or on a small area.

Q3. What is the best cleaner for outdoor paver stones?

It depends on the type of paver. Although a cleaner may be suitable for use on concrete or clay pavers, it may not be suitable for limestone or sandstone. It is important to test the cleaner on the type of paver first. As a rule of thumb, there is no single product that is suitable for all types of pavers.

Q4. Is bleach safe for outside pavers?

Bleach will have an adverse effect and discolour natural stone (such as limestone or sandstone), depending on the type. Read the product and ensure it will match the type of paver.

Q5. Is it safe to use vinegar on paver stones?

Vinegar is acidic and won't be suitable to use on natural stone, especially limestone or sandstone, which are very porous and may be etched. As a general rule, it is best to avoid using acidic products on natural stone. When employing a product, it is also crucial to ensure that it is compatible with the type of paver.

Q6. How often do garden paver blocks need to be cleaned?

It will vary based on the type of paver and the location it is applied to. Shade, tree roots, dampness and the type of paver will all impact how fast dirt and staining occur, so regular sweeping combined with a thorough cleaning regimen as required is best.