Indian sandstone is the stone I clean more than any other in Liverpool. It’s everywhere. You’ll find it on driveways and patios right across the city. And it comes with its own set of habits, ones I’ve got very used to dealing with over the years. So here’s what’s actually going on with it.
What Is Indian Sandstone
Why It Goes Green and Black So Fast
How I Clean It
Sealing: Worth It or Not
How Often Should You Clean It
FAQs
Get a Quote
What Is Indian Sandstone
It’s a natural sedimentary stone, quarried mostly in Rajasthan. It comes in raj green, autumn brown, kandla grey and a few other shades. It’s sold as riven paving, which means the surface has a natural split texture rather than being dead flat. That texture gives it character. But it also holds onto dirt and moisture in a way a flatter surface wouldn’t. That’s a big part of why I’m called out to it so often.
Why It Goes Green and Black So Fast
Liverpool doesn’t help. We get more rain than most of the country. And because Indian sandstone is porous, it holds moisture in the surface long after a flatter stone would’ve dried out. Add shade from a fence or a north-facing garden, and you’ve got the perfect breeding ground for algae and moss. The green is algae, feeding off the damp. The black staining you sometimes see, especially in the low points where water pools, is usually a mix of algae and general grime working its way into the pores.
So I see this on driveways that are barely two years old. It’s not a sign anything’s gone wrong. It’s just what this stone does if it’s left alone.
How I Clean It
For a driveway, I’ll go over it first with the pressure washer to lift loose dirt and debris. Then I apply sodium hypochlorite where it’s needed. This kills off the algae and moss at the root, rather than just blasting the surface layer away. After that, I go in with the twin-jet surface cleaner. Two rotating jets give you even coverage without leaving stripe marks, which is a real risk with a single-jet wand on a stone this soft.
For anything in the joints, or stubborn build-up in the texture, I might bring in the turbo nozzle. But I’m careful with that on sandstone, because it’s soft enough that too much pressure in one spot can start eating into the surface. You’ve probably heard the horror stories, someone’s mate did their driveway and it looks patchy now. That’s usually too much pressure held in one place for too long, on a stone that can’t take it.
Sealing: Worth It or Not
Honestly, yes, for this stone specifically. Because it’s so porous, a decent sealer makes a genuine difference to how long it stays clean, and to how easy the next clean is. I wouldn’t say the same for every type of stone, some really don’t need it. But Indian sandstone benefits more than most. It won’t stop algae forming forever, nothing does that, but it slows things right down and stops staining soaking into the stone itself.
So if your driveway’s never been sealed and it’s a few years old, I’d get it properly cleaned first, then sealed once it’s fully dry. Sealing over dirt just traps the problem underneath.
How Often Should You Clean It
For most Indian sandstone driveways round here, once a year keeps it looking right. If it’s shaded, north-facing, or near trees, you might need it every 8 months. Patios in sunnier, more open spots can sometimes stretch to 18 months. It genuinely depends on the spot. That’s why I always ask for a few photos before quoting, rather than guessing off a postcode. And if you’ve got a different stone entirely, it’s worth a read of how York stone or granite hold up in comparison, since they behave quite differently.
FAQs
It’s porous and holds moisture. Even a driveway laid last year can show algae within months, especially if it’s shaded or doesn’t dry out properly between rain.
Yes, but carefully. Too much pressure held in one spot can damage the soft surface. This is where a proper twin-jet surface cleaner earns its keep over a handheld wand.
I’d recommend it. It’s one of the more porous stones we deal with. Sealing genuinely extends how long it stays clean.
Every driveway’s different in size and condition. So I always quote after seeing photos rather than guessing. WhatsApp me a few pictures and I’ll get you a proper number, usually within about 5 minutes.
Done properly, no. Done with too much pressure in one place for too long, yes. That’s when you get patchy, worn-looking patio stones. It’s about technique, not the stone being fragile.
You can, with a domestic pressure washer. But go steady, keep the nozzle moving, and don’t expect the same finish as a proper twin-jet clean. Chemical treatment for algae is where most DIY jobs fall short, a hose down alone won’t kill the spores underneath.
A bit. Lighter colours like autumn brown show black staining more obviously. Raj green and kandla grey can actually hide some staining, though the algae’s still there either way.
That’s usually efflorescence, salts coming up through the stone as it dries out. It’s common on newer sandstone and usually settles down over the first year or two.
With a good clean and sealing, most driveways stay looking sharp for 12 to 18 months before you’d notice it creeping back.
Get a Quote
If your Indian sandstone’s looking tired, send us a few photos on WhatsApp. We’ll get you a price, usually within 5 minutes. Quoting this way also gets you 10% off, since it saves us the fuel and the time of coming out just to look at it.