How to Get Rid of Stubborn Black Spots on Your Patio – For Good

By Mark Cave March 30, 2025

How to Get Rid of Stubborn Black Spots on Your Patio – For Good

The Hidden Enemy on Your Patio

You’ve power-washed. You’ve scrubbed. You’ve spent hours trying every cleaner on the shelf.

And yet… those ugly black spots on your patio just won’t budge.

Whether you’re a homeowner trying to restore your beautiful Indian sandstone or a professional cleaner facing another tough job — black lichen and deep organic staining can feel impossible to remove. They ruin the look of your outdoor space and make even the best patios look tired and neglected.

And worse still? Even when you get rid of them temporarily… they come back.

Why Black Spots Are So Hard to Remove

Black spots are typically caused by a type of lichen — a hardy, biofilm-based growth that anchors deep into porous surfaces like sandstone, concrete, or block paving. They can survive harsh weather and resist pressure washing and over-the-counter chemicals.

In fact, many homeowners and even some pros end up damaging their patios by using excessive force or strong acid-based cleaners that strip away the surface of the stone.

So what’s the answer?

The Proven 3-Step Method to Remove & Prevent Black Spots

At SoftWash UK, we’ve spent years perfecting a professional-grade system that not only removes black spots effectively, but also prevents them from coming back.

Here’s the exact method professionals across the UK are now using:

Step 1 – Break It Down with Sodium Hypochlorite

Our high-strength Sodium Hypochlorite (20L) gets to work fast. It penetrates deep into porous surfaces, killing off the lichen and loosening its grip. This chemical has been a staple in professional exterior cleaning for a reason — it works.

But on its own, it can run off too quickly on vertical or porous surfaces.

Step 2 – Boost Power & Stick with Clever Wash

This is where Clever Wash, our softwash surfactant, changes the game. It helps the Sodium Hypochlorite cling to surfaces longer, improves penetration, and even makes rinsing easier. It’s biodegradable, bleach-safe, and designed specifically for exterior cleaning professionals.

With this pairing, you’ll see a visible difference within minutes — even on patios that haven’t been cleaned in years.

Step 3 – Keep It Clean with SoftWash Pro 50

Once your patio is clean and looking refreshed, it’s time to lock in those results.

SoftWash Pro 50 is a powerful biocide that prevents algae, mould, and lichen from returning. It goes deeper into the surface and keeps working long after the initial treatment. This means you won’t be dealing with regrowth next month — or even the month after that.

Safe, Professional-Grade Products for Everyone

Whether you’re a seasoned softwash contractor or a homeowner looking for better results, our products are:

REACH & HSE Compliant
Biodegradable and safe when used correctly
Trusted by professionals across the UK
Available online with fast UK delivery

No More Guesswork. No More Scrubbing. Just Results.

You don’t need to spend hours battling your patio.

You just need the right products, in the right order.

Our Black Spot Removal Trio (Sodium Hypochlorite + Clever Wash + SoftWash Pro 50) is trusted by professionals, simple enough for homeowners, and gives you the confidence that your outdoor spaces will stay looking great — without pressure washing damage or ineffective store-bought sprays.

Ready to Restore Your Patio?

Get everything you need to remove black spots and prevent them from coming back.
Shop now at:
https://www.softwashing.uk

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Soft Wash Calculator App

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Softwashing calculator is an indispensable tool for juggling complicated chemical mixes. It helps reduce wastage and keeps operating costs down by giving accurate proportions

If you are having difficulty getting your head around the maths, trying to work out what percentage of softwash you need, how much chemical, surfactant and water to add, then this is the App for you.

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It doesn't stop there!.
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- works in both Litres and US Gallons
- tested for Protan and Deutan colourblind users
- links to SoftwashingUK website

Take this scenario
You started with a 1% soft wash recipe of 50 gal (or litres) for a deck clean and you’re left with 13 gallons.

You get a call from a prospective customer to clean their roof. Past experience tells you a 4% soft wash recipe is needed, but what about your leftover mix at 1%?.

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You could consider the 13 gal as just water, top up the tank and start again.
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Soft Wash Calculator App to the rescue.

You get to the new job and it requires 100 gal / litres.
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The same applies if you have a 4% recipe left in your tank and you need to dilute it down to 2%. Again the app will tell you how.

Softwashing calculator will also work for any chemical recipe. For instance you can use it for Sodium Hypochlorite, Bleach, Biocide , TFR traffic film remover and degreaser. Even the mathematically-challenged rocket scientist can top up their booster tanks to new fuel mixes after launch delays caused by changing weather conditions.

Using this app you will know exactly what chemical strength to put on any surface giving you the confidence and the knowledge of a professional soft washer and you’ll save money as well.

So if you have little knowledge of how to mix a soft wash recipe then this app is for you.
If you have little knowledge of how to remix a soft wash recipe then this app is for you.
If you want to save money when mixing a soft wash recipe then this app is for you.

This app is also backward compatible to devices running iOS7. We've done this so you can re-purpose an old iPhone 4 or iPod Touch 5 for what could be hazardous work environments. Just toss one in your cleaning van's toolkit.

Once you learn the methods and procedures of how to apply the soft wash to the different surfaces that need cleaning you’ll be unstoppable!

The app also has a guide to what percentage for what surface. And if you are the lucky owner of a Clever Injector it will remind you the correct setting for the job.
However you should always consider and risk assess what soft wash recipe you need to clean the surface.

** A major iOS code-base change may require a re-purchase. The appiverse at the time will confirm our promise that we won't do so unless the necessity is apparent.

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