How to Clean an Indian Sandstone Patio (And Keep It Looking Great)

Indian sandstone is one of the most popular patio materials in the UK — and it's easy to see why. Its natural colour variation and warm tones look beautiful when first laid. But over time, organic staining, green algae, and black spots can make even the most stunning sandstone look tired and neglected.

The good news? Restoring it is easier than you think.

Why Does Indian Sandstone Get Dirty?

Indian sandstone is a porous natural stone, which means it absorbs moisture — and with moisture comes organic growth. Algae, moss, and black spot fungus thrive in the damp UK climate, particularly in shaded or north-facing areas. Pressure washing alone often isn't enough to shift stubborn staining, and over time it can actually damage the surface.

What You'll Need

• A pump-up garden sprayer (5–7 litres)
• A pressure washer for rinsing
• Stone King Indian Sandstone Cleaner

Step-by-Step: How to Clean Indian Sandstone

1. Clear the area — remove furniture, pots, and any loose debris.
2. Pour Stone King into your garden sprayer — no dilution needed.
3. Test a small area first — spray a 1m x 1m patch and saturate thoroughly.
4. Wait 15 minutes — you'll see a colour change as the cleaner gets to work.
5. Leave for 2 hours — this allows deep cleaning action to break down stubborn staining.
6. Rinse off — lightly pressure wash the area.
7. Repeat if needed — for heavily stained areas, re-treat until the staining is gone.
8. Treat the rest — once you've seen the results, work across the full patio with confidence.

Is It Safe for Pets and Plants?

Yes — Stone King Indian Sandstone Cleaner is pet-friendly and biodegradable. We recommend keeping pets off the area while applying, but once rinsed off it's immediately safe.

How to Prevent Staining Returning

Once your sandstone is clean, apply Patio Black Spot Preventer annually. It removes algae within 3–5 days of application and prevents black spot from returning — keeping your patio looking great with minimal effort year after year.

Ready to restore your sandstone? Shop Stone King Indian Sandstone Cleaner and Patio Black Spot Preventer.