35p vinegar from the kitchen cupboard: cleaning moss and algae from your patio

The answer came from the kitchen cupboard.

Anyone with a patio will recognise the issue: as soon as the cold, damp months have passed, moss, algae and black marks begin covering the slabs. Specialist cleaners can easily cost £20 or more, while a pressure washer is noisy, cumbersome and far from neighbour-friendly. In my case, a basic household product costing just 35p ultimately made the difference – without any expensive professional equipment.

When the patio becomes a slip hazard

By spring 2026, my concrete patio was almost unrecognisable. The spot where the barbecue stands in summer was covered with a slippery green film. Every step felt precarious, and a chair rocked on the surface because cushions of moss had formed beneath the furniture legs.

At the DIY shop, shelves were stacked with containers of green-growth removers, their labels promising results that were “quick”, “powerful” and “instantly clean”. The drawbacks were the high prices, strict safety instructions and biocides carrying environmental warnings. The other option was a pressure washer: hiring it, carrying it, connecting it up – and using a tool that is not exactly gentle on the surface.

So I looked for something that met three requirements:

• as inexpensive as possible
• easy to use without much physical effort
• no arsenal of harsh specialist chemicals

The answer came, of all places, from an account shared by a British colleague – and an unassuming bottle of household vinegar.

The 35p kitchen-cupboard product

The “star” of this cleaning story was clear household vinegar: a standard vinegar cleaner without additives. On supermarket shelves, a bottle can cost less than 40p. According to the tip, the same product that removes limescale from taps or descales a kettle could also tackle moss and algae on paving.

“A simple vinegar-and-water mixture, an hour of time – and the patio suddenly looked as though it had just been laid.”

The principle is straightforward: the acid in vinegar attacks the fine structure of moss and algae, loosening the growth so it can be removed with minimal brushing. There is no pressure jet that might wash out joints or roughen delicate surfaces.

Step by step: how the 1-hour test worked

I recreated my British colleague’s method as closely as possible, and the result surprised even me. These are the individual steps as they worked in practice.

1. Sweep thoroughly before spraying or pouring anything

First, I went over every slab with a broom. It was necessary to remove not just surface dirt, but also leaves, sand and loose clumps of moss. A yard broom or a stiff scrubbing brush is suitable for this.

• sweep away loose leaves and twigs
• clear sand and soil from the joints
• loosen thick patches of moss mechanically

This stage determines whether the vinegar solution can actually reach the growth later on, rather than simply sitting on top of remaining dirt.

2. Mixing ratio: how much vinegar and how much water?

Next came the bucket. The basic formula was one part vinegar to one part water. The tap water should be lukewarm rather than hot, so the acid remains stable.

Example for a medium-sized patio:

Amount of vinegar	Amount of water	Coverage area (approx.)
1 litre	1 litre	up to around 10 m²
1.5 litres	1.5 litres	up to around 15 m²
2 litres	2 litres	up to around 20 m²

I mixed half a bottle of vinegar with the same amount of water. This was enough to soak the heaviest green growth precisely, without flooding the entire patio.

3. Apply the solution and leave it alone for an hour

Rather than spraying laboriously, I slowly poured the bucket’s contents over the affected areas and spread it lightly using the brush. The important point is to make the growth genuinely wet, not merely dampen it briefly.

“At least 30 to 60 minutes of contact time makes the difference – this is where the real ‘work’ happens.”

During that time, I could get on with other household jobs without any problem. There was no scrubbing on my knees and no noisy motor, just a damp patio surface quietly “working” away.

4. A light scrub – and the dirt lifts almost by itself

After nearly an hour, I used the hard-bristled broom again, this time as a scrubbing tool. With moderate pressure, I worked across the slabs one row at a time.

The striking part was that the dark green areas became lighter immediately beneath each brush stroke. Instead of simply smearing, the coating broke away properly. On particularly stubborn patches, a second, more concentrated treatment with a little fresh solution helped.

Finally, I rinsed the patio with the garden hose. Anyone without a hose can rinse it using a bucket of clean water.

Where the vinegar patio method works well – and where it is risky

Although the result was convincing, the vinegar method cannot be used without care on every surface. The patio material is crucial.

Suitable surfaces

• Concrete slabs: robust and relatively insensitive to mild acids, making them ideal for this use.
• Frost-resistant ceramic or porcelain tiles: generally fairly resistant, but test a discreet area first.
• Exposed aggregate concrete slabs: growth usually lifts very effectively here, while the joints are barely sensitive.

Take care with natural stone and certain joints

• Marble, limestone and some sandstones: acid can leave the surface dull and stained.
• Polished granite: it is best not to treat this with vinegar, as its appearance can quickly suffer.
• Cement joints around glazed tiles: it makes sense to carry out individual tests in edge areas.

“If you are unsure, test the mixture in a hidden corner first – a small patch tells you more than any theory.”

How does vinegar compare with chemical anti-moss products?

Anyone facing a heavily weathered patio will soon ask: is vinegar really enough, or is a container from the DIY shop still necessary? A brief comparison highlights the differences.

Cost and effort compared

• Vinegar solution: only a few pence per square metre; a bucket and broom are all that is needed.
• Anti-green-growth container: around £4 for 5 litres, usually covering larger areas but involving more demanding safety rules.
• Pressure washer: hire charges or purchase costs, electricity or petrol, and spray everywhere.

When it comes to cost, vinegar is clearly ahead. Regular cleaning also prevents thick growth built up over years from forming in the first place.

Environmental and health considerations

Many anti-moss products contain biocides designed specifically to kill algae and moss. If they reach flowerbeds or drains, they can harm plants and micro-organisms there. Their labels often require:

• protective gloves and sometimes eye protection
• no contact with pets while the surface is drying
• no application in windy conditions, so that nothing is blown away

Vinegar is not pure natural magic either: at high concentrations, it can scorch plants in a flowerbed. However, used in moderate quantities on sealed surfaces, it will normally place substantially less strain on the environment than many specialist products.

Practical tips for the next patio clean

Anyone wishing to copy the vinegar method can benefit from a few practical tricks:

• Choose dry weather: rain would dilute and wash away the mixture too quickly.
• Wear light protective clothing: simple rubber gloves protect hands from irritation, while old shoes are sensible.
• Keep pets away: it is better not to let them walk over the area while it remains wet.
• Green growth in joints: use a narrow brush to target these areas, press in the solution and wait longer.
• Regular “refreshing”: a shorter treatment in early autumn prevents everything becoming clogged again over winter.

What else helps to stop moss taking over

Vinegar cleans the patio, but it does not remove the causes of moss and algae: moisture and shade. A few everyday adjustments can help keep the problem under control.

• Remove leaves regularly: layers of damp foliage act like a breeding ground.
• Raise plant pots slightly: this allows less moisture to collect underneath them.
• Improve air circulation: where possible, thin out shrubs slightly so more wind can reach the surface.
• Check the gradient: water should be able to drain away instead of remaining in puddles.

Anyone who keeps these points in mind and uses a vinegar solution once or twice a year can stop the patio becoming a constant concern. The method is no replacement for professional repairs where slabs are damaged, but it shows how much a simple household remedy can achieve before turning to costly or aggressive specialist products.