As paving experts, GGM Landscaping is here to teach you what works and what damages paving when cleaning. Get great results without wrecking your slabs in the process.
Before You Start Cleaning Paving
This may sound like common sense, but make sure you remember to move all your garden furniture, plant pots, barbecues, and anything else sitting on the paving before you start.
You need clear access to the whole surface, because patchy cleaning looks worse than not cleaning at all.
Once the area is clear, give it a thorough sweep with a stiff yard broom to remove loose debris, leaves, and surface dirt.
Pull out any weeds growing between the joints by hand or with a weeding tool. This matters more than you might think, because scrubbing over weeds just pushes green staining deeper into the stone, and it makes it harder to shift later.
If there’s heavy moss growth on the surface, scrape off the bulk of it with a flat-edged spade or a stiff brush before you apply any cleaning solution. You want to be cleaning the paving itself, not washing the moss around.
Once all the prep work is complete, you will be pleased to know that there is a variety of ways to clean your paving.
Method 1: Warm Soapy Water to Clean Paving
If you are dealing with general dirt and grime, this is the simplest approach and the one we’d recommend trying first.
Fill a bucket with warm water and add a big squirt of washing-up liquid. Nothing fancy, no specialist products needed.
Let the solution sit on the surface for at least ten minutes to break down the dirt, then scrub again and rinse with clean water from a bucket or garden hose.
Work in sections rather than trying to do the entire patio at once, because the soapy water loses its effectiveness as it cools and gets dirty with dirt and debris.
For most lightly soiled patios, this may be all you need to remove dirt and general build-up.
Method 2: White Vinegar on Paving Slabs
White vinegar is a popular choice for paving that has a green tinge from algae or light moss growth.
The natural acidity breaks down organic matter without introducing harsh chemicals, and it’s cheap enough that you won’t mind using plenty of it.
It is also a great alternative to using salt to kill weeds.
Mix equal parts white vinegar and warm water in a watering can or bucket, pour it over the affected area, and leave it for 15 to 20 minutes before scrubbing and rinsing thoroughly.
There’s an important caveat here, though.
Vinegar is acidic, and acid doesn’t agree with every type of stone. If you’ve got natural sandstone or limestone paving, vinegar can cause discolouration or etch the surface, particularly on lighter-coloured slabs.
It’s perfectly fine on concrete paving and most porcelain, but always test a small area first and wait for it to dry completely before judging the result.
If you’re unsure what is the best way to clean your type of paving, skip the vinegar and stick with soapy water instead.
Method 3: Pressure Washer on Patios
A pressure washer will shift dirt, moss, and staining that no amount of manual scrubbing can touch. It’s the most effective method for heavily soiled paving, and if you don’t own one, they’re widely available to hire.
That said, pressure washing is also the method most likely to cause damage if it’s done carelessly.
The best way to use a pressure washer is by holding the lance at least 30 centimetres away from the surface.
Getting too close to stubborn stains concentrates the jet. This can chip the face of softer stone or blow the jointing sand straight out from between the slabs.
Keep the angle around 30 to 45 degrees to the surface rather than pointing straight down, and work methodically in one direction so the dirty water runs away from the area you’ve already cleaned.
Pressure washers are brilliant on concrete flags, block paving, and porcelain. They need more care on natural sandstone and limestone, where the softer surface can be etched or pitted by too much pressure.
Once you’ve finished, check the joints on your driveway or patio. If the jointing compound or sand has been disturbed, you’ll need to re-point before weeds find their way back in.
Method 4: Specialist Paving Cleaners
There are dedicated paving cleaning products available from most DIY shops and builders’ merchants. These are formulated to clean stone without damaging it, and they’re worth considering if you’ve got a particularly stubborn problem or an expensive natural stone patio.
The main advantage of specialist products is that they’re pH-balanced for the material they’re designed to clean, so there’s less risk of discolouration or surface damage.
Follow the manufacturer’s instructions on dilution ratios and dwell times, and always test on a small area first.
Although they might cost more than other methods, it can be worth the peace of mind, if you have invested in quality paving.
Dealing With Specific Stains on Patio Slabs
General cleaning will handle most everyday dirt, but some stains need a more targeted approach.
Grease and oil
Grease stains from barbecues and oil stains from parked vehicles won’t respond to water-based cleaning. The ways to deal with oil stains depends on how long it has been present on the slabs, with longer stains needing additional measures.
Luckily, we have made a full guide on different ways to remove oil stains from paving slabs.
Rust marks
Metal furniture legs or tools left on the paving can leave rust marks. This can usually be treated with lemon juice and salt.
Apply the mixture, leave it for a couple of hours, then scrub and rinse. Commercial rust removers are available too, but check they’re safe for your paving type before applying.
Again, because of the high acidicy from the lemon juice, always test before using to avoid discolouration.
Moss and algae
If moss and algae keep growing, it might be a sign of poor drainage or heavy shade.
Cleaning will remove the growth, but it’ll return unless you address the underlying cause. Improving drainage, cutting back overhanging branches to let more light onto the paving, and applying a proprietary moss inhibitor after cleaning can all help slow regrowth.
Which Method Works Best to Clean Paving Slabs
The material your paving is made from determines which cleaning methods are safe to use and which could cause lasting damage. Just remember this is a general guide, and we always recommend testing before going ahead with a particular method.
Concrete slabs and block paving
These tend to be the most forgiving slabs. Soapy water, bleach (diluted), vinegar, and pressure washing all work well. Concrete is hard-wearing and tolerates most household cleaning products without issue.
Natural sandstone
Sandstone is more porous and softer than concrete, so it absorbs stains more readily. This makes it easier to damage.
Avoid vinegar and undiluted bleach.
Soapy water and specialist stone cleaners are the safest options. If you’re pressure washing, use a lower setting and a wider fan nozzle.
Porcelain paving
Dense, non-porous, and very hard-wearing, making it resists against staining. Soapy water and pressure washing work well. But avoid bleach, as it can affect the surface glaze on some porcelain tiles.
Indian sandstone
This varies quite a lot depending on the grade and quarry it came from.
Lighter colours can yellow with bleach, and cheaper grades are more porous and stain-prone.
When in doubt, use warm soapy water and a specialist sandstone cleaner. It’s worth spending a bit more on the cleaning product to protect a surface that costs you considerably more to install.
Contact GGM Landscaping for Paving Advice and Installation
If your paving is looking like it has reached the end of its lifespan or if you are tired with constant upkeep, GGM Landscaping’s team is here to help you.
We design and install paving solutions which are built to last. But we don’t just install paving and walk away. We are here to look after outdoor spaces long-term, from regular grounds maintenance to full patio restorations.
Contact our friendly team today for a free consultation on 07946 322717.