GK Pro 5Ltr (Professional use only)
GK Pro 5Ltr (Professional use only)

GK Pro 5Ltr (Professional use only)

£94.80 INC VAT
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  • Estimated Delivery:Apr 20 - Apr 24

  • Free Mainland UK Delivery : On Orders Over £100


This product is approved by the HSE (no.10766) for application by professionals only, by ticking this box you are agreeing that you meet these requirements.

I agree to the terms and conditons.

Image from - DM Cleaning of Shedfield

Before and After

GK Pro applied to Render

Product in use

Images from - Wolf Building Maintenance Services GK Pro Applied to various surfaces

Product Description

GK Pro is primarily designed to combat moulds, algae, lichens, and various biofilms and has quickly become a favourite within the professional cleaning and maintenance sector, establishing itself as the preferred choice for tackling stubborn biological growth. It uses a natural surfactant cleaning action to achieve predictable results every time. Upon application by brush or spray, its vigorous foaming becomes a recognisable indicator to ensure complete coverage of the intended cleaning area.

Applied at low pressure, GK Pro minimises the risk of damage, avoiding the harsh impact of scouring, scrubbing, or water blasting. This is a versatile solution appropriate for nearly any hard substrate, excluding only green or sedum roofs. It’s especially good for use with delicate surfaces like historic thatch, as it can be used without compromising the integrity of the material.

GK Pro is chemical-free, steering clear of the harsh components typically found in bleach-based cleaners. When used according to instructions, GK Pro avoids oxidation or negative impacts on hard surfaces, even safeguarding lead works, UPVC windows, and seals.

This powerhouse solution operates with precision, targeting living cells to serve as a highly effective sanitiser, eliminating 99.9% of bacterial matter. For smaller areas, no specialised equipment is required; a simple garden sprayer will suffice. However, in these instances, the use of appropriate personal protective equipment (PPE), including gloves and eye/face protection, is strongly recommended.

At the core of GK Pro's effectiveness lies its active ingredient, DDAC, ensuring residual activity that actively prevents premature regrowth.


 HSE (no.10766) Following a routine check from HSE we can confirm that our product formulation is as stated.

Key Features

• Versatile Hard Substrate Use: Suitable for almost any hard substrate (excluding green or sedum roofs), making it ideal for historic and fragile surfaces, including thatch.

• Gentle Low-Pressure Application: Applied at low pressure, GK Pro minimises the risk of damage often associated with harsh scouring, scrubbing, or water blasting.

• Chemical-Free Assurance: Free from harsh chemicals found in bleach-based cleaners, GK PRO, when used as instructed, does not oxidise or negatively impact hard surfaces, including lead works, UPVC windows, and seals.

• Effective Sanitisation: Acts only on living cells, serving as an effective sanitising agent for 99.9% of bacterial matter.

• HSE Certification: Following a routine check from the HSE (no.10766), we confirm that our product formulation aligns with the stated information.

Application Guidelines

GK Pro is a professional cleaning agent - conversation with your preferred GK Pro applicator will determine the right course of action for
your property.

GK Pro should be applied during a dry, relatively wind free day with no likelihood of rain for at least four hours and in temperatures
above 5°c.

A spray treatment with GK Pro works in conjunction with natural weather cycles of UV, to desiccate the now dead, bacterial staining while rain will remove the powdery residue. This process, being weather driven, can take many weeks before your building will look “as new”, but the process is predictable, and it will happen.


Store the product securely in a locked-up area in its
original container, storing it in a cool, well-ventilated space away from any combustible materials and heat. For a more comprehensive understanding, refer to the Product Information section 7.2 for conditions of safe storage, including incompatibilities.

Technical Data Sheets

GK Pro - HSE licence number : 10766

Review by Partridge Exterior Cleaning.

Roof soft washing with GK Pro

Partridge Exterior Cleaning are exterior cleaning specialists based in Burton-on-Trent. Sid is gaining a sound reputation for Roof Cleaning, Driveway & Patio Cleaning, and Gutter cleaning. He is becoming quite a YouTube sensation offering advice and good technical expertise to anyone who asks. Sid is genuinely a nice bloke and has a large following on his channel.

Product FAQs

How long will it take GK Pro to work?

This is dependent on the biological loading of moulds and algae, however GK Pro will kill biological growth on application, although it will take time for the effect to be seen.

Mild staining, results can be seen within days.

Heavier loads can take 2-3 months to see radical improvements.

In severe cases of contamination, it may take 6-12 months to work or to see the full results.

The reason for this is part of the removal process is dependent on the weather cycles to remove detritus and biological contaminants on our behalf.

However, the effects of subsequent applications or maintenance cycles will be seen quicker and usually within days.

When it it best to apply?

t can be applied all year round however results may be affected if rain occurs within 24 hrs and if temperatures are below 8 degrees Celsius.

As a minimum it is recommended that the product is applied on a dry day with little or no wind, and when rain is not likely for a minimum of 4 to 5 hours with temperatures at 5 degrees Celsius and rising.

Optimum gains can be made in warmer weather, and in conditions where there is minimal evaporation, allowing the surface to remain wet for longer, giving the product time to work.

Is GK Pro safe around children and pets?

Once dry GK Pro is safe around children and animals, however good practice is to keep them away during application.
GK Pro is plants safe provided you do not spray them directly. If you accidently overspray onto them, rinse down with clear water from a hose. It may scorch foliage, but it should not kill plants and grass lawns recover very quickly. It is good practice to protect them with waterproof fabric covers or plastic prior to spray.

On what surfaces can I use GK PRO, and will it cause any damage?

GK Pro is bleach, ammonia, acids, and solvents free.

GK Pro will not 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.

It can be used on virtually any outdoor surface including tarmac, bricks and paving, concrete, decking, roof tiles, render, solar panels, 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. It can also be used to clean painted surfaces without the risk of damaging the paint film.

When used on decking, it can reduce the risk of this becoming a slip hazard, by removing bio films that contribute to decking becoming slippery.

Can I change the suggested dilutions given in the instructions?

Yes. If the staining is extreme, a stronger concentration will bring a quicker reaction.

However likewise, if you have cleaned the surface previously and you are simply providing a routine maintenance spray, as contamination is light, you can decrease the strength and the cleaning process will still be effective.

GK Pro is more effective in warmer weather and concentration levels can be reduced, however equally in colder conditions, concentration can be increased to facilitates results. Our dilutions rates are based on providing a baseline application that should work consistently

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.

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