Sandstone is one of the most welcoming paving stones there is. Its warm, earthy tones suit almost any garden, and it only looks better for a little care. But it is also a natural, porous stone, which means that left alone, it will quietly collect dirt, algae and stains. The good news is that cleaning it is rarely difficult. This guide explains how to clean sandstone paving, including Indian sandstone, using gentle methods that protect the surface rather than strip it.

Why regular cleaning matters for sandstone paving

Sandstone is durable, but it is made of tiny grains of sand held together naturally, with small pores in between. Those pores are part of its character, and they are also why the stone can absorb dirt, damp and stains over time.

Outdoors, the usual culprits are moss, algae, leaf stains and general grime, particularly in shaded or damp corners of the garden. Left to build up, they dull the colour of the stone, make the surface slippery underfoot, and can encourage deeper staining that is harder to shift later. A regular, gentle clean keeps the natural colour and texture of your sandstone looking as it should, and helps it last.

What you'll need to clean sandstone paving

You do not need specialist equipment. For most gardens, this is enough:

• A soft brush or broom
• A bucket or watering can
• A stone-safe cleaner, such as LTP Grimex, which is formulated for natural stone and contains no bleach
• A hose, or a pressure washer on a low setting (optional, and used with care)

Avoid acidic or harsh cleaners. They can etch the surface of the stone and leave it looking patchy or stained, and the damage is not easy to reverse.

Pro tip: always test your chosen cleaning product on a small, inconspicuous area first. Let it dry fully before judging the result, as sandstone often looks different wet.

Step-by-step guide: how to clean sandstone paving

1. Sweep and remove debris. Clear leaves, soil and loose surface dirt with a broom, so you are cleaning the stone rather than pushing mud around it.
2. Wet the area. Dampen the paving with clean water first. A pre-wetted surface absorbs less of the cleaning solution, which helps prevent patchy marks.
3. Apply the cleaner. Apply LTP Grimex, or your chosen stone cleaner, exactly as the manufacturer instructs, covering the area evenly. Work in sections so it does not dry on the surface.
4. Scrub the surface. Use a nylon pad or a stiff-bristled brush, but not a wire one or any abrasive tool, to work the solution in and lift dirt and algae.
5. Rinse thoroughly. Wash away all the residue with clean water. Leftover cleaner can leave a film and attract more dirt.
6. Repeat if necessary. Heavily soiled or stained areas may need a second clean. It is better to repeat a gentle clean than to reach for something harsher.

How to clean Indian sandstone paving

Indian sandstone is one of the most popular paving stones in the UK, so this is the question we hear most. The short answer is that you use the same gentle process as above, with a little extra care. Indian sandstone is more porous than porcelain or granite, so it takes in water and cleaning products more readily, and it is more easily marked by aggressive cleaning.

To clean Indian sandstone paving slabs, follow the steps above, and avoid jet washing where you can, as it can erode the surface and leave a rougher, lighter-looking finish. Once the stone is clean and fully dry, it is worth sealing it to help prevent future staining. Our guide to laying paving covers the practical side, and our patio grout is worth a look if the joints need refreshing at the same time.

What is the best solution for cleaning Indian sandstone?

For everyday dirt and general staining, the best solution for cleaning Indian sandstone is a dedicated, non-acidic natural stone cleaner such as LTP Grimex, which we recommend using once or twice a year. Apply it as the manufacturer instructs, scrub gently, then rinse well. For green growth and black spot, use a targeted treatment such as LTP Blackspot and Algae Remover instead. Whichever you choose, test it on a small area before you start.

Removing algae, moss and stains from sandstone

Algae, moss and lichen thrive in damp, shaded areas, which is why they often appear first on north-facing patios and beneath overhanging trees. To remove algae from sandstone paving:

1. Brush away loose growth with a dry, stiff brush.
2. Apply an algae remover, such as LTP Blackspot and Algae Remover, which is bleach-free and made for patio paving and driveways. Follow the product instructions.
3. Leave it to work for the time the manufacturer recommends. Most biocides do the work slowly, so you may not see a change straight away.
4. Rinse gently with clean water.

For rust marks from metal furniture, BBQs or fire pits, LTP Rust Stain Remover is a non-caustic option. For rust breakouts, cement or mortar residue, LTP Ferrex Patio Cleaner & Rust Remover is an acid-based cleaner suitable for sandstone, so follow the label closely, including dwell times, and rinse thoroughly. For other marks, a stone-specific stain remover is usually safer than home remedies. Treat marks as soon as you spot them, as fresh stains lift far more easily than old ones, and always test first.

Preventive tip: improve drainage and, where you can, let in more light by trimming back overhanging branches. A drier, sunnier surface is much less welcoming to regrowth.

Can you use a pressure washer on sandstone?

It can be done, but we would generally recommend avoiding it. A pressure washer is quick, but sandstone is softer than many people expect, and too much force can erode the surface and cause chipping or etching. If you do use one, follow these steps to keep the risk down:

• Use a low to medium pressure setting, typically between 1,500 and 2,500 psi.
• Fit a wide-angle nozzle, such as a 25 or 40-degree tip, not a narrow jet.
• Keep the nozzle around 18 to 24 inches (roughly 45 to 60cm) from the surface.
• Work in small sections with a steady sweeping motion, and avoid lingering in one spot, as prolonged water exposure can lead to efflorescence (white salt deposits).
• Avoid blasting the joints and the edges of the slabs, which can wash out the jointing material.
• Do a test patch first, and let the stone dry completely afterwards.

If you are in any doubt, a hose and a brush will do the job more slowly but more safely. You can explore our stone-safe cleaning and sealing products for long-lasting results

Sealing and long-term maintenance tips

Sealing clean sandstone helps protect it against stains, algae, dirt and weathering, including frost damage, by reducing the amount of water the stone absorbs. We recommend LTP Mattstone H2O, a water-based impregnating sealer for exterior stone that protects against water, oil and grease without adding a glossy sheen. To revive faded colour, LTP Colour Intensifier and Stainblock H2O deepens the stone's natural tones while protecting it. Whichever you choose, make sure the paving is completely clean and dry before you apply it, and follow the manufacturer's instructions, including the temperature range and how long to keep the surface dry while it cures. A simple routine keeps sandstone looking its best:

• Light clean every few months, or whenever it looks tired
• Deep clean once or twice a year
• Reseal every one to two years, depending on wear and weather exposure, or as the product recommends

Common mistakes to avoid when cleaning sandstone

• Using acidic or bleach-based cleaners
• Overusing a pressure washer
• Skipping the rinse, which leaves residue behind
• Cleaning in freezing or very hot weather, when products can behave unpredictably
• Sealing before the stone has fully dried

Pro tip: gentle, consistent care keeps sandstone looking natural and bright for years.

Frequently asked questions

How do you clean Indian sandstone? Sweep the area, wet it, apply a diluted pH-neutral stone cleaner, scrub with a brush, then rinse thoroughly. Avoid strong jet washing and harsh chemicals.

How do you clean algae from sandstone paving? Brush off loose growth, apply a stone-safe algae remover or biocide, leave it for the recommended time, and rinse gently.

Can you jet wash Indian sandstone? It can be done, but we would generally recommend avoiding it. If you do, use a low to medium pressure (typically 1,500 to 2,500 psi), a wide-angle nozzle, a safe distance and a test patch first. Strong jetting can erode the surface.

How often should sandstone paving be cleaned and sealed? A light clean every few months, a deep clean once or twice a year, and resealing roughly every one to two years, depending on wear and weather exposure.

Final thoughts: keep your sandstone looking its best

Sandstone's timeless look deserves a little care. Clean it gently, seal it once it is clean and dry, reseal when it needs it, and keep up with regular maintenance, and it will keep its colour and character for years to come.

About the Author

Sian McHugh

'Sian has been working with us at Westminster Stone for over 7 years and has developed expertise in garden design and landscaping. Her passion for nature extends to tending her own garden, teaching yoga and hiking during her free time.'