Which Softwash Chemical is Best to Use?

Most "dirt and grime" on exterior hard surfaces is actually an organic colonisation of algae, lichen, fungus and mould. Soft washing is the process of killing and removing these growths (aka "biofilm") to reveal the clean surface they were covering up.

What's the difference between our softwash chemicals?

Softwash cleaning chemical biocides

Benz Bio Cleanze and Lightning Cleanze are both government approved softwash biocides. They are both used to treat biofilms on exterior hard surfaces.

They have different active ingredients, work differently, and are used for differing soft washing applications.

The practical "how-to" of soft washing

Bio Cleanze is our "Spray-And-Leave" softwash biocide with the advantage of offering deep cleaning through time. It's used on roofs, render, paths, car parks, etc – in fact pretty much any exterior hard surface.

Bio Cleanze is excellent for maintaining and cleaning surfaces with light to medium colonisation, particularly stone, render and roofs.

This powerful ddac-based biocide can be applied by spraying, or brushing for more stubborn colonisations which are often coloured dark red or black. It has the advantage of being able to penetrate exceptionally deep into the biofilm of a treated surface.

The cleaning action of Bio Cleanze continues over time through natural weathering by sun, rain and wind. You'll usually see the first results within 24 hours, with further improvements within two weeks. Gradual ongoing deep cleaning will continue for several months following a treatment.



Benz Lightning Cleanze is also a softwash biocide, with the advantage of being faster acting than Bio Cleanze. It's particularly useful for an initial treatment of surfaces with medium to heavy soiling, and for contracts that require very fast results.

The cleaning effect of Lightning Cleanze is almost immediate. However, because it is denser than water it cannot penetrate porous surfaces to the same depth as Bio Cleanze.

Depending on the level of colonisation, Lightning Cleanze can be used in two ways:

  1. As a stand-alone biocidal softwash cleaner.
  2. After rinsing it can be followed by a treatment of Bio Cleanze, resulting in the most powerfully effective soft wash treatment possible.

By utilising these two chemicals in this synergistic (1+1=3) manner, you can achieve highly effective results without using high concentrations of either product. This saves you money and saves our environment from exposure to unnecessarily strong chemicals.

Quick tip: Surfaces with heavy to extremely heavy colonisation often benefit from a pre-treatment with Bio Cleanze two weeks to three months before treating with Lightning Cleanze. This is a particularly useful practice for the treatment of sand and cement render prior to painting.

IMPORTANT: Never mix Bio Cleanze and Lightning Cleanse together because toxic chlorine gas will be produced. Post-treat a Lightning Cleanze treatment with Bio Cleanze only after thorough rinsing.

What chemical dilution should you use?

Use the tables below to determine the most effective dilution for the surface you are going to treat. In certain instances, a single product treatment will suffice, while for others, a combination of two treatments may be necessary.

Ultimately it will be your hands-on experience that will be your best guide. But start out by cross-referencing between these tables to determine the most effective dilution to use for your particular contract and the results your customer wants you to achieve.

For more detailed information about keeping surfaces consistently clean throughout the year, take a look at Benz "Clean & Maintain Systems".





Quick Tip: Whichever softwash chemical cleaning method you choose, it's important to identify the original cause of the organic colonisation and reduce, and preferably eliminate, it to ensure the long-lasting results your customers want and will be delighted with.

Find all the soft washing info you'll ever need – watch this short video to discover how: