Case Study: What type of render was used on this tower block?

Project Info

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    Recent Projects

The project

Spectrum was initially brought onto this project to help identify the type of render that had been used to finish this tower. The housing association that manages the block wanted to have the façade cleaned, but needed to assess the materials used on the exterior of the property before they could proceed.

Thanks to our extensive experience cleaning modern render, we were able to identify the type of render that had been used on the building. This allowed us to create a comprehensive plan for cleaning the façade and restoring the property to its original aesthetic condition.

One of the challenges of this project was the building’s painted façade. The presence of paint on the surface makes the cleaning process more complicated. In cases where the render has been finished with paint, it’s even more important to identify the correct render and the correct cleaning method for the job.

As well as restoring the modern rendered façade, the housing association asked Spectrum to clean the property’s windows, frames and walkways. This was all done as part of the service. An impressive 70% of cleaning on this project was carried out using our patented render cleaning process from the safety of the ground.

The site

This tower was made up of more than seven storeys and contained a large number of flats. In order to minimise disruption to residents and ensure the clean was quick and efficient, we planned to use ground-based operatives wherever possible. As part of the building’s rendered façade was painted, we needed to assess the condition of the surface and the materials used before we could begin.

The logistics

Our unique approach to modern render cleaning minimises the need for scaffolding and heavy machinery. In many cases, it negates it altogether. At the site, we planned to use ground-based operatives for the majority of the clean. The rest of the work would be carried out via rope access. As there were no anchor points on the property, we used our own portable anchorage for abseiling safely. This system is called an A-frame.

As our operatives were required to abseil onto balconies in order to clean them, they needed to remove the pigeon netting that was in place. Temporarily removing the netting allowed our team better access to the balconies and ensured they were able to clean every part of the rendered surface.

As a large proportion of the netting was old, damaged and weathered, our operatives carried out significant repairs to the netting when re-installing it. Taking the time to repair the netting protected the balconies from birds’ mess and ensured the exterior of the property looked as good as possible on completion of the clean.

One thing that was different about this project was the painted surface of the property. Parts of the modern render on the Tower had been painted to create a feature wall. A lot of people believe that once modern render has been painted, it cannot be cleaned and must be painted again. Luckily, in some cases, it is possible to clean painted modern render. However, it is important to ensure the original paintwork was done properly before proceeding.

To ensure our patented render cleaning technique would do the job effectively, we carried out a number of tests on the property before starting the clean. These samples were successful and so we went ahead with cleaning the painted sections of modern render.

The clean

Cleaning the exterior of this tower required both ground-based operatives and rope access. Due to the height of the building and the number of balconies, around 30% of the clean was carried out via rope access.

All operatives who carry out render cleaning abseiling have undergone the relevant Work at Height training. They are also IRATA certified, a qualification that takes up to five years to achieve. This ensures all work on terraces and raised elevations is done safely and correctly. Our team have also completed COSH training for correct usage of the biocide application.

In order to properly clean buildings with modern render like this site, our team have an understanding of BS EN 13914-1:2016. This covers the design, preparation and application of external rendering and internal plastering. A knowledge of this standard helps our operatives identify the type of modern render used on a building. This helps us assess the condition of modern render and create a comprehensive plan for the clean. 

When this site was first surveyed, it was unclear exactly what type of modern render had been used. We were able to identify the render by examining the pours and finish of the product. Properly classifying the render ensured we were able to use the right level of treatment when cleaning the surface.   

When cleaning the modern render on this tower, we used our patented P.A.S.T. system. This process uses steam heated to 150 degrees to clean the surface of the render and a biocide treatment to kill algae and prevent regrowth.

As the render on this site was porous, achieving the results we did would not have been possible without using 150-degree steam. The steam, even at a low pressure, is integral in removing the heavy stains that can be found in polluted city environments.

Our patented 4-stage cleaning process involves:

P: Preparing the render and the area for cleaning

A: Application of biocide to the render

S: Steam cleaning at 150 degrees to the render

T: Targeted treatment to any stains on the render

This project was a good example of the reach of our patented equipment. While we needed to use rope operatives to clean around 30% of the block, 70% of the work was carried out from the safety of the ground. Our cleverly designed system allowed our ground-based operatives to clean above the 7th floor of the property. In fact, the equipment almost reached the 8th storey of the tower.

The result

It took a total of 4 operatives to complete the modern render clean on this Tower. We used our patented equipment to remove staining and algae from the surface of the building and restore the render, including painted sections, to its original aesthetic condition.

Around 70% of the work was carried out from the ground and 30% was completed by rope operatives. Using this approach, rather than scaffolding and heavy machinery, is estimated to have saved the client 60% on access costs alone.

As well as cleaning the render our team carried out extensive repairs to the pigeon netting protecting the building’s balconies. Going above and beyond to repair this netting shows just how dedicated our team are and demonstrates our values of authenticity, care and excellence. 

We were very pleased with how the painted section of render responded to the clean. Prior to work commencing, it was unclear whether or not it would be possible to clean the painted surface to the required standard. With our expertise and understanding, we were able to select the right approach and restore the painted surface.

On completion of the project, the client said, “We couldn’t believe how high the equipment reached.” While an operative said, “It was great to make such a big difference on such a difficult to access building” and Lucian, the MD, remarked “It was a great case study to show how our patented system and P.A.S.T. process effectively cleaned render that had been previously painted.”