render maintenance

Everything in life needs a little TLC from time to time.  You visit the dentist…your clothes, windows and car will need a wash…your shoes need a polish..your grass needs cut…your garden needs tending and your hedge needs a trim.  Your render will also need some TLC from time to time.  We offer a number of products to help you keep your render looking sharp and performing as it should for many years to come.   At Rowebb we supply render so the cleaning products we supply are designed specifically to clean our renders..

Render maintenance and cleaning is an important part of your annual building maintenance programme however there are a few key points to establish at the outset to ensure the future of your render is bright.  Firstly, don’t let any of these questions frighten you.  If you are not sure, then take a picture and send it over to us and we should be able to help you from there. 

What type of render do you have?  Is it a cementitious scratch render, a silicone or acrylic based thin coat render, a floated painted smooth render, a drydash or a wetdash render?  Once this is known then the cleaning method can be established.  What is causing the issue with your render?  Is it algae, dirt and grime, red staining, oxidisation, run-off from an external fitting, an issue with the render itself or general render fatigue?  Once the reasons for the issues have been identified, a solution and maintenance programme can be established.

Some renders have a fragile surface and any treatment needs to be carefully applied and left to work its magic, whilst others offer a more robust surface and can cope with some gentle agitation or softwashing during the treatment.  Green, red, and black algae all require slightly different approaches and water staining, oxidisation and render fatigue may require further investigation and remedial works.

In general, most renders require a good clean and then some isolated repairs and some attention to construction details to prevent future issues, although many buildings just require a good clean down.




With the extensive range of products we have available, most eventualities can be addressed and it is just a clients choice as to how much work is done whether this be just a clean down, render repairs or a clean and reproof.

A small area of render should be checked prior to cleaning to check the compatibility of cleaning solution with the specific render.  This wont give a full indication of the final appearance, but it will identify any issues prior to the work starting.  Most situations do not require any agitation but it may require a second or third treatment to achieve an acceptable result.

Our products have been developed by the render industry for use by the render industry.  They are not general cleaning products and as such they have been developed to work in harmony with the type of renders used in the construction industry today.  Our products don’t negatively impact the long term performance of the render but have been designed to get into the nooks and crannies of the render and clean more than just the surface.  We don’t aim to saturate the surface like some manufacturers as the contamination is very often only present on the very top surface and complete saturation can lead to other issues with render failure and debonding in the future.  That is why we sometimes need repeat treatments to achieve the best result.

We do not recommend high pressure washing of render. Smooth renders can be washed using the most gentle setting on the spray nozzle under strict controls and by a very experienced contractor however, drydash renders should never be washed under any more pressure than a gentle rinse with a garden hose.  We feel a gentle approach with repeated treatments is better than using a sledgehammer to crack a nut!!  

Our technical team is on hand to advise you on 0141 548 6010.



This render cleaner is designed to make an instant impact. Use it straight from the bottle and apply using a sprayer. Just spray it on and leave to do its magic for half an hour or so and then wash off with lots of fresh water. 

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An algicide compatible with K-Rend renders

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Applied by a sprayer after being diluted to the required strength, Alkem will kill the algae living on your render. It takes time to work and may require another treatment after a couple of weeks to get the best results. Alkem is best used as a preventative treatment as it will kill the algae spores and prevent excessive growth during the year.

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Whilst this is an acid free cleaner, it is designed for more stubborn stains and contamination. Always handle and use with extreme caution.

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A heavy duty acid cleaner for extreme use only and used as the last resort. Please call for details and guidance.

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Propel is a water displacement product designed to improve the longterm performance of your render. By stopping moisture sitting on the surface, algae growth will be dramatically reduced. It is important that any repellent product is more breathable than the render below and has been designed for this type of application.


 K Pro is a water based protective treatment used to provide long term, enhanced water repellent properties to external render and other masonry surfaces.



JUB Acrylcolor is used to over-paint thin coat renders and both new and old cementitious renders. Offering a high degree of weather performance and durability, excellent adhesion properties and vapour permeable, Acrylcolor will not bubble or peel.


JUB Silicatecolor is designed for over-painting older cementitious renders. Being extremely breathable and with the addition of micro fibres this paint is an excellent choice for renovating old renders. Creating a chemical bond between the paint and the substrate, Silicatecolor ensures long term performance and adhesion.


JUB Nanocolor is a micro reinforced self cleaning paint for areas of high exposure to weather and pollution. This paint offers the highest level of water and dirt repellence. It offers excellent resistance to algae and mould and is available in broad range of colours.


Designed to over paint new render whilst retaining some of the original texture. A range of colours to mimic the K-Rend scratch render range.


K-Rend Silicone Paint is available in a range of colours that mimic the K-Rend standard colour range. Offering improved performance, this silicone based paint can be used over new and older scratch renders and K-Rend thin coat renders.


Parex Revlane paint is designed to over-paint Parex thin coat and scratch renders.