I regularly hear people proclaim that their monocouche or through coloured scraped renders are "non maintenance," when they speak to me and they are a little flabbergasted that they are getting told that their render needs cleaning. This is a common misconception because of the misunderstanding of what "non maintenance" actually means.
Modern renders are incredibly hard wearing; a correctly applied system will withstand many years of whatever the elements throw at them even in sometimes extreme circumstances. Everyday I drive past a rendered property that was rendered nearly 30 years ago which even though the property has been subject to heavy flooding over 8ft deep at numerous points in history still looks great today, with no sign of the render falling off anytime soon.
On that basis, all modern renders are almost certainly expected to be non-maintenance. Once they are on, you'll have a hell of a time to get them off and re-applying anytime of the next couple of decades and beyond certainly should not be needed.
This doesn't mean that some, not all, will need some kind of regular cleaning. This is the case for all properties in the UK, regardless of what the walls were made up of. Thankfully its not a overly difficult task to either take preventative measures to minimise the amount of cleaning needed in the first place or to clean after things start to look a little dirty.
If you have signs of algae growth, we'd recommend you be proactive and kill it with a good algae cleaner before it gets chance to spread, we have them available on our site here or here. These tend to incredibly easy to apply as they simply are sprayed through a normal garden low pressure spray. Algae is stubborn stuff, it can grow on anything given the right conditions and its better to nip it in the bud before it spreads.
Light pressure washing is something that can be done also as long as care is taken not to apply too much pressure to the surface of the render which may damage the surface. Industrial washers may have too much power for this job, but your average consumer grade washer that you buy from B&Q should be fine. Good quality non-acidic patio cleaners applied before washing down will also help with dirt removal.
If you are looking to prevent dirt and algae build up completely you could use a special sealer for these types of surfaces. We will shortly be launching a new product we have developed called ProtxSeal which is incredibly easy to apply, again using a low pressure sprayer. Using a formula containing Siloxanes, ProtxSeal completely repels water and seals the render with a lotus leaf effect seal whilst still allowing the walls to breathe. Dirt and algae simply gets washed away as it can no longer stick to the surface. This sealer is easy to apply through a normal garden spray, does not change the appearance of the render at all and can be used on ANY porous masonary surface. We will also shortly be offering application services also for this product, please contact us for more details.
If you need any advice on how to keep your render looking fantastic for years to come do not hesitate to give us a call.