MINERAL PROTECTION FOR WOOD
A SUCCESS STORY
Wood is probably the oldest building material used by humans. Its advantages are its high availability, the fact that it is easy to process and that it provides a good interior living climate. When correctly processed, wood can last for hundreds of years – countless wooden structures across the globe are an impressive testament to this.
Wood is a renewable resource that is characterised by its longevity and robustness, its good insulating properties and its contribution to the energy efficiency of buildings. Wood regulates humidity and absorbs harmful substances out of ambient air inside rooms and interior spaces. Wood not only creates a better world, but also a more pleasant interior climate.
THE BUILDING MATERIAL FOR THE 21st CENTURY
Wood is experiencing a real renaissance in modern architecture. Innovative production methods are making completely new ways of building possible. Wood has the potential to become the building material of the 21st century.
Wood lives and works and, as a natural material, is a demanding material to work with. In order for wood to maintain its natural beauty, it needs protection, especially outdoors against: moisture, UV radiation, chemical and biological influences..
LONGEVITY AND RESISTANCE
The appearance and longevity of a wooden façade depends on what materials, construction and surface treatment are chosen. In order to meet the structural-engineering needs with respect to longevity and optical durability, KEIM offer protection measures in the form of suitable coatings.
Going beyond purely maintaining the building, painting also provides the possibility to be aesthetically creative in order to underline the individual character of a wood structure or wood-inspired interior..
Due to its swelling and shrinking behaviour, wood poses a significant challenge for coatings.
Conventional wood coatings are based on linseed oils, alkyd resin, acrylates and other plastics. They are used to reduce the ingress of moisture and the destruction of the lignin through UV light. The binders contained in these organic coatings are not permanently UV resistant, however. This first results in changes to the colour or the shine and, after that, the decomposition of the binder.
When the elasticity starts to decline, the coating becomes brittle, flakes off and loses its protective effect. Moisture gets into the parts of the wood that are now open, moves behind the still intact coatings, increases the "movements" of the wood and so accelerates the destruction process.
Conventional wood coatings have a limited service life of approximately 3 to 7 years, depending on the quality and stresses involved.
Silicate paints consist of inorganic binders, mineral fillers and inorganic colour pigments. They cure due to a chemical reaction of the binder with minerals in the substrate, which combine insolubly with each other. Silicate paints have proved themselves to be extremely weather resistant and permanent on mineral construction materials. Due to their typical matt-lime appearance and the purely inorganic pigmented shades of colour, they have particularly proved their worth when it comes to the maintenance, protection and design of buildings.
After 20 years of research, the product developers at KEIM have been successful in transferring the silicate paint principle to wooden substrates. This involves two tried-and-tested coating materials being combined: oily primer with good ingression properties & silicate paints which provide reliable protection against exposure to weather and UV light.
Due to the longevity which is typical for silicates, the coating structure of KEIM Lignosil is extremely durable and ensures that Lignosil surfaces do not usually need to be sanded before being renovated. A thorough cleaning of the surfaces is fully sufficient as preparation.
The KEIM Lignosil coating protects and maintains the modern and historical structures and convinces with clear advantages:
• low diffusion resistance
• excellent moisture protection
• extremely weather resistant and durable
• UV-stable and absolutely lightfast
• matt, monument-appropriate appearance
• easy to renovate
• tested in accordance with DIN EN 927
• safe due to tried-and-tested individual components
SPECIAL CASE "CONTROLLED GREYING" OF WOOD
A QUESTION OF AESTHETICS
The attitude of architects and builders towards this is almost as controversial as the phenomenon itself: accept and allow nature to run its course or try to control the development of the surfaces with coatings. There is now an elegant way out of this dilemma: With KEIM Lignosil-Verano, a silicate-based surface treatment which has been developed that simulates a naturally beautiful silver-grey patinised wood appearance from the very first day. As a result of the conscious waiver of the protective function, as is desired in the case of coatings, the coat of Lignosil-Verano applied goes more and more over to a natural greying as time passes. No subsequent coats need to be applied – the elegance of the greyed wood facade develops without any further effort or action being required.
What makes it so special? KEIM Lignosil-Verano does not contain any biocides or solvents and guarantees an appearance with a stable and natural mineral matt colour. The treated surfaces remain open to diffusion. As well as being fast drying and extremely simple to process, Lignosil-Verano is a particularly economical and sustainable system.