Maintaining a smart frontage

Although not a recent innovation, self-cleaning renders and paints have made an indelible mark on the construction industry as an ingenious alternative to regular and aggressive building renovation, writes Nikolaos Mantelis, Product Manager at global building materials manufacturer, Baumit.



roducts which require water or natural elements such as daylight, rain or air moisture to keep a building’s facade clean offer a huge benefit to the property owner in terms of cost-effectiveness.

Self-cleansing systems eliminate the need for periodical maintenance as surfaces stay looking clean and healthy far longer than traditional coatings. The environment gains from the technology, too. Buildings adorned with self-cleaning materials do not require chemically-infused agents to maintain a dirt-free surface. A fact worth remembering as the Government struggles to make good its pledge to reduce UK emissions by a minimum 80% from 1990 levels by 2050.

Bright solution

The two main self-cleaning topcoat systems currently available require different climatic conditions to trigger the cleansing process. One uses direct rain or water contact, allowing dirt contained within a droplet to simply roll off the surface. This system is fine in principle, but slightly flawed in practice. The electrostatic properties of the molecules contained within the topcoat means if a hand or other object such as a ball comes into contact with the surface, a dirty print will be left behind. Nanopor is different.

Nanopor systems require nothing more than sunlight, humidity and wind to provide a uniform, dirt-free surface. A special photocatalyst additive, which has been developed by Baumit, uses the power of light to activate the self-cleaning effect in its Nanopor range of renders and paints.

The ‘Nanopor-effect’ is produced when sunlight activates the photocatalysis additive in the render or paint, affecting the upper-hydrophilic nano layer within the product whilst it dries. During the process, dirt is decomposed and lifted from the surface by air movement. Any remaining particles are removed by rain and evaporation of absorbed dampness. For a simpler explanation of the ‘Nanopor-effect’; when a drop of water falls on a normal hydrophobic render surface, it will appear as a ‘ball’ of water. A drop of water when dropped onto Baumit NanoporTop loses its surface tension. During evaporation the moisture releases dirt particles, resulting in a dry, clean and beautiful facade.

Sustainable alternative

Because Nanopor doesn’t depend on direct contact with water to trigger the self-cleaning process, areas of a building not exposed to rain – such as those beneath the eaves – are also thoroughly cleansed. This enables a consistent, clean performance across the entire building and eliminates issues such as streaking or dark patches forming where water was unable to connect with the facade.

The photokat process is particularly effective against fungi or mould in a facade. It’s also superb for removing smoke or dust particles. Again, it’s worth making the point that the innovative Nanotechnology in renders and paints reduces the need for a building’s renovation, making it a cost-effective and environmentally-friendly alternative to other exterior coatings.

As with most self-cleaning exterior finishes, Baumit NanoporTop, a ready-to-use dirt and pollution-repellent render, can be hand- or machine-applied. It features unique nano-crystalline and non-organic additives which result in significant surface reduction of pollution compared to other coatings, leaving a building protected and looking clean and bright. The microscopically smooth surface of Baumit Nanopor render and paint offers a facade a unique protective barrier against pollution, as dirt particles have nothing to cling onto.

The development of self-cleaning top coats and renders has given a whole new lease of life to building facades. Focusing as much care and attention to the array of available technically-advanced, high-performance materials we apply to the outside of a building, will help ensure a more comfortable and healthy environment for those on the inside.

Share this article

Login to post comments

About us

Future Constructor & Architect is a specification platform for architects and building contractors, which focuses on top-end domestic and commercial developments.

As well as timely industry comment and legislation updates, the magazine covers recent projects and reviews the latest sustainable building products on the market. Subscribe here.

Privacy policy

Latest updates


Sign up below to receive our weekly building product updates e-newsletter and our monthly digital magazine editions from FC&A via email: