Re-colonisation – How long does residual biocide protection last for?

January 13, 2021

Benz Bio Cleanze DDAC softwash biocide for professional soft washing

How long will a property remain clean after being treated with Benz Bio Cleanze or Perma Cleanze (both products have the same active ingredient: ddac).

Firstly, pressure washing without post-treating with Bio Cleanze or Perma Cleanze will always result in rapid re-colonisation.

But fortunately Bio Cleanze and Perma Cleanze have the ability to offer long-term "residual biocide protection" against the recolonisation of porous surfaces.

This quality is the reason why they are the main products used in our "Clean & Maintain" softwash systems.

Quick tip: Residual biocide protection only works on porous surfaces, not on smooth, non-porous surfaces such as roof slates or metal cladding.

How long does residual biocidal protection last?

Because of the many variables involved (material the treated surface is made of, local environment, care taken by a customer, skill of the contractor, prevailing weather, temperature, strength and quantity of product applied, etc, etc) it is not possible to give a "one size fits all" estimate of the exact time during which a given property will be protected from recolonisation.

Will a lot of plant life close to the area being treated increase the probability of rapid re-colonisation? Yes, so if your customer is willing to pay a bit more give the surface a light jet wash followed by a treatment of Lightning Cleanze 5:1 prior to treating with Bio Cleanze.

Removing the worst of the colonisation before treating with Bio Cleanze allows the chemical to work more effectively, faster, for longer (because less of its biocidal power is used up in killing the colonisation, and so is available for ongoing protection).

Another tip for extending the long-term results of a treatment is to find out what your customer is doing with grass and hedge clippings, leaves, etc. Even a small quantity of grass cuttings, clippings from foliage, or leaves left on a concrete, block or tarmac surface for a surprisingly short time, will encourage re-colonisation, which then spreads.

So educating customers about what they can do to help keep their property free from colonisation by some good housekeeping – cleaning under flower pots, removing clippings, frequently brushing away organic matter, etc, can help extend the length of time a treated surface remains clean.

Should you offer your customers a guarantee and/or a contract?

Our domestic customers tend not to ask this question as they trust us to do the best possible job for them using the most effective soft wash cleaning products.

We simply contact them every 6-36 months (timescale depends on the surface, e.g. patios can be 6-18 months, walls 12-36 months, roofs up to 3 years or more) to offer them a repeat application of Bio Cleanze as part of our "Clean & Maintain" service.

Our customers are always delighted to find that regular repeat applications usually costs much less than the original treatment.


Quick tip: Perma Cleanze is formulated for safe and legal use by the employees of property maintenance companies, in-house cleaning staff, and the general public. Most professional soft wash cleaning contractors will use Bio Cleanze.

Your commercial customers may sometimes want a more formal agreement, so you could offer them a "Clean & Maintain" contract in which you guarantee to keep their property clean for a year at a time, during which time you will return to re-treat a surface should that be necessary (which it rarely is).

With an annual contract in place, once the property has been initially cleaned using Benz Lightning Cleanze and/or Tornado Cleanze, all that is necessary is to give a yearly treatment of Bio Cleanze to give your customer a permanently clean property.

You'll find that your customers will love this approach, as opposed to the more common once-off soft wash treatment, then leaving the property to get dirty for several years before a customer cannot live with the dirt any more and wants it cleaned again.

The principle has similarities to the regular cleaning of windows to give a customer permanently clean windows rather than allowing them to become seriously dirty before cleaning them again.

The approach of waiting until a customer cannot stand the filth anymore creates considerably more work for a contractor – and therefore is much less profitable – and customers do not get to enjoy a permanently clean property.

Quick tip: Regular soft wash cleaning treatments are a win-win for both contractor and customer. The customer gets a permanently clean property, and the contractor regular repeat business.

We sincerely wish you great success in your soft washing business,

Ben, Leo, Fiona, Stevie & Anthony

PS: Safety & effectiveness: If animals and/or children will use a horizontal surface there's no option other than to limit the strength of applied Bio Cleanze to 50:1. But pre-treating with Lightning Cleanze and/or jet washing will help extend the time that Bio Cleanze will protect against re-colonisation.

Click here to get more practical how-to tips about re-colonisation
Quick tip: Enter a relevant "keyword" or short phrase into our in-site Search Engine to find answers to most of your soft washing questions (e.g. keyword for above link = "re-colonisation")


You can order Benz softwash chemicals & equipment online or by phone:

GB (England, Scotland, Wales)

Phone: 0800 70 74 222 


Ireland and other countries

Phone: 00353 214 622 978


Lines open Monday - Friday, 9am – 5pm

Please note: The above numbers are for orders only (click here for tech support)

Click here to explore the full range of Benz softwash cleaning chemicals & equipment

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

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