How to softwash natural and man-made stone

April 03, 2019

 Click here to explore Benz Softwash Bio Cleanze DDAC biocide & Benz Softwash Lightning Cleanze SH sodium hypochlorite biocide

We've been asked for information regarding softwashing stone. As we said to our customer, there's not a lot to say other than ...

Benz Bio Cleanze, Perma Cleanze, Lightning Cleanze and Tornado Cleanze are all suitable for cleaning natural stone, man-made stone, hard stone and soft stone.

We sell two softwash biocides: Bio Cleanze and Lightning Cleanze.

And now we have Benz Tornado Cleanze, which removes the most ingrained black, green, red and yellow staining (caused by algae, lichen, moss and mould) from stone, concrete, brickwork, uPVC and most other external hard surfaces.

Specifically, Tornado Cleanze quickly removes black and white lichen (aka "Black and white lichen dots, or black and white lichen spots), black and green algae, yellow lichen, and moss from stone paths, stone patios and stone walls.

Tornado Cleanze is particularly valuable for the softwash cleaning of vertical stone walls when you need a product that with "super-stickability" that will cling to the surface and not run off.


Click here to download our Product Documentation Pack – which contains all the information you need – including SDS, PDS, dilution rates and application methods. – for all our softwash products.

The photo below shows the versatility of Bio Cleanze (30:1 after 4 months) when softwashing wall render, a concrete kerb and stone chippings




On the whole, for non-porous hard stone such as granite, you’ll find Lightning Cleanze and/or Tornado Cleanze produce the fastest and most effective results. And they are highly effective when used to offer stand-alone treatments.

For soft, porous stone such as sandstone, Benz Bio Cleanze comes into it’s own as a post-treatment because it’s extremely good “wetting” characteristics – it's a more effective wetting agent than water – allow it to soak deep down under the surface.

This enables Bio Cleanze to kill any remaining spores that may have remained deep within the permeable stone. It can also be used as a stand-alone treatment for hard stone such as granite.

This also means that – after killing the remaining spores – this powerful product will offer longer-term residual protection from re-colonisation than is possible when softwashing with a sodium hypochlorite product alone.

Quick tip: As with any surface and product you are not 100% certain will be compatible, always (with your customer's permission) treat a small, out of the way test area first.


A stone surface – whether natural stone or man-made stone, hard stone or soft stone – should not require re-treating for several months after being cleaned with Lightning Cleanze or Tornado Cleanze.

The time after which re-treatment with Bio Cleanze will become necessary is far greater, although because of the numerous variable factors it is impossible to quote a definite period.

The exact time-scale depends on the local environment, the care that your customer takes of their property, and the proximity of trees, bushes, plant pots and so on.

Quick tip: After the first treatment, remember to put your customer onto an ongoing scheduled "Clean & Maintain" programme, which will keep your customers happy by giving them a permanently clean property – and give you, the contractor, a nice repeat income.

We hope this information is helpful.


Ben, Leo & Fiona

Click here to learn more about softwashing via Benz Trade Tips softwashing how-to posts

The Benz Softwash range of softwash cleaning products

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to explore the full range of Benz popular softwash cleaning products

Benz Softwash Bio Cleanze DDAC biocide & Benz Softwash Lightning Cleanze SH sodium hypochlorite biocide

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