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Soft Wash Render Cleaning - Immediate Results, Clean and Protect from re growth

Our first objective with the soft washing products we use are to clean gently, leave no trace on the building substrate, to have consideration for the environment and to ensure no adverse effect on pets plants or humans.
Second we want our soft washing products to clean thoroughly, removing even the most stubborn black encrusted biofilms and then to protect the render from the biofilm re establishing as best we can.
So we have two stages of soft washing, the same technique, but with two soft washing products……. clean, then protect.
The protection soft wash product will keep the biofilm at bay for about a couple of years. A re application of our soft wash protection product at that point and then regularly every couple of years or so will keep your rendered wall in great shape.

PHONE TO 01268 722 500


 wall render cleaning

01268 722 500

Renders and soft washing - how they react to being cleaned

Renders come in different forms and understanding the makeup of your render is the crucial first step in determining how to use soft washing to clean it. The basic renders coating our walls are pebble dash, lime render, cement render and K-Rend. All of these render finishes have pores or an open structure that’s highly convenient for dirt and grime to collect and for organic life forms to inhabit. These renders can be deeply porous, hard or soft and can be soft to the point of being powdery where even a light hosing will leave marks, especially if a film of algae has developed and weakened the surface. Every day of the week they are subjected to a wide range of hostile weather systems, from freezing temperatures to rain and wind promoting erosion of the surface, with rain in some instances keeping the rendered wall wet for extended periods of time, especially on surfaces with minimal sun exposure. Care is always needed when soft washing and in this assessment phase, as consideration needs to be given to the composition of the render, and how well the product sticks to the wall. Poorly mixed renders or renders with the incorrect ratio of original ingredients, or indeed the addition of plasticiser additives (to make the render easier to work with), may suffer from a lower adhesion especially when attacked by an aggressive biofilm, therefor prior to soft washing we need to be sure of the wall render recipe.

Soft Washing the Biofilms

Biofilms are what we are trying to eliminate when soft washing, they are an organic mix of algae, lichens, moulds, fungi and mosses. Their make up on any one surface is as varied as the number of surfaces out there. Around our built environment, they live on sandstones, brickwork, roofs of all types, walls, driveways and paths, fences and decking and can make our lives hazardous. Some individual species in the biofilms could be lichens that are in fact classed as endangered species. This has been the case with the high amount of pollution in the environment causing the acid rain that destroys these plant forms. Things are changing with cleaner vehicle emissions, generally cleaner air, and bans on certain pollutants means that some lichens are making a comeback. So an unexpected result in some ways has resulted in much more aggressive biofilms on buildings sometimes when and where we least expect it and usually where it is inconvenient, causes damage, downright dangerous or just spoils the view. We don’t do soft washing on monuments. By definition they are usually in an area of historical or archaeological importance and is not our area of soft washing expertise, and biofilms on ancient monuments or gravestones may contain endangered species of lichens.
There is an opinion out there that biofilms including lichens and moss are an attempt at conservation or preservation, even to the point where the biofilm can damage the structure of a building and there is a resolute stubbornness to accept the plain truth that biofilms in forests, ancient monuments or ancient woodlands where nature intended them to be are just great, but not on our homes. However pro green you may be, you may live in a home that might be manufactured from unsustainable sources, there is overwhelming evidence acknowledging that biofilms can have an adverse affect on our homes and health. Moulds are part of this ecosystem and have been shown to give great discomfort to sufferers with bronchial problems and asthma.

Control of biofilms in the built environment, inside and outside our homes, should be done sensibly to enhance our lives but giving thought to the natural environment around us.

Biofilm Development

Lets specifically talk about wall renders we want to softwash. The first phase of biofilm development is the accumulation of grime, simple dirt. If the surface of the render was a tight packed very dense polished surface then pollens, spores and other forms would not settle so easily. However, wall render is very open and porous and provides the perfect haven for the accumulation of mould and algae. Even so the filaments of aggressive fungal form may only penetrate to 1mm depth into the render, however if not remove intelligently, the marking they leave behind can be very noticeable. Soft washing the render will in time result in all the resulting scarring being healed with the action of the soft wash products and sunlight. Mechanical removal unlike soft washing will leave its own marking, even worse than the biofilm, and can result in irreversible scrapes, smoothed areas and polished areas with the wall render being scarred for ever.

If you've got the slime, we've got the time ….! "