Frequently Asked Questions

How long will it take for GK Pro to work?

It is dependent on the biological loading of moulds and algae. Mild staining, results can be seen in days. Heavier loads can take 2-3 months to see radical improvements – We rely on repeated cycles of weather to remove detritus on our behalf. In severe cases of contamination, it may take 6-12 months to work. However, the following season, after a light maintenance spray results will be within days


Is GK Pro safe around children and pets?

Once dry yes – as with all wet work it is best practice to keep them away during application. If you are concerned that natural evaporation takes too long it is fine to thoroughly rinse with clear water after an hour or so


Will it damage plants?

Only if you spray directly onto them. If you accidentally overspray on to them rinse down with clear water from a hose, it may scorch foliage but it will not kill your plants, grass lawns recover very quickly – it’s good practice to protect them with waterproof fabric covers or plastic prior to spray.


Does it remove slime from timber decking?

Yes! Regular use will prevent your deck becoming a slip hazard. If the deck is old and has never been cleaned, it may be useful to wait for a month after application to give the deck a brush or scrubbing with warm water to remove aged black staining. You should only have to do this once and annual the maintenance is then easy.


Will GK Pro & Greener Kleener damage my render, concrete, decking or paths?

No – guaranteed GK Pro is free of bleach, ammonia, acids, solvents or any other chemical . The products cannot interact with any substrate or product that is not living and, unlike many other cleaners is non-oxidising so will not damage your outdoor surfaces.


How much area does GK Pro cover?

Each 5 litre pack can be diluted into 250 litres to make 255 litres of product to spray. Using a garden sprayer, you will get coverage of around 1,250 square metres. Some surfaces (i.e. painted or cladding) will use less but porous surface coverage could be in the range of 1,250 square metres – the dilution should be halved if used on a tiled roof.


Can I change the suggested dilutions given in the instructions?

Yes. If the staining is extreme a stronger concentration will bring a quicker reaction. Likewise, if you have cleaned the surface previously and you are simply providing a routine maintenance spray, you can decrease the strength if the contamination is light. The cleaning process will still be effective.


Can I paint or stain over surfaces treated with GK Pro & Greener Kleener?

Yes. Once clean and dry. It is great for extending the life of painted surfaces - the natural surfactant removes dirt & grime that causes fading and chipping as does keeping it free of moss, mould and algae. An annual treatment on outdoor hard surfaces will extend help your cyclical painting routines


How soon after applying can I start painting?

If you leave the dead bacterial growth to start decomposing for 2-3 weeks prior to painting (or staining), wash the surface, the dirt and residue will be easily removed. The surface will also be sanitised reducing the likelihood of new paint being contaminated with algae and fungi.


On what surfaces can I use GK Pro & Greener Kleener?

Virtually any outdoor surface including tarmac, bricks and paving, concrete, decking, roof tiles, Astroturf, canvas tents, caravans, conservatories, fibreglass boats, polytunnels, limestone, sandstone, marble, outdoor furniture, outdoor pots, outdoor painted surfaces, pool surrounds, slate, non-grass tennis courts, yacht sails.


Can I use GK Pro and Greener Kleener on wood?

Yes. Under the EU biocides register both are classified as “wood preserver” so can be used on decking, shed, fences, window frames and wooden garden furniture, it will prevent wood rot and disinfect as well.


How should I prepare the surface before applying GK Pro and Greener Kleener?

Remove any excess debris and bulky vegative growth, do not wash the surface immediately prior to application as GK Pro and Greener Kleener should be applied to a dry surface.


When is it best to apply?

On a dry day with little or no wind and likely to be rain free for 4 to 5 hours. A cooler day/time of day gains optimum performance as evaporation is minimal, ensuring the treated surface stays wet for an extended period.


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