Natural timber is a wonderful material for construction and timber construction is sustainable building because most timber is now produced by plantation methods from land, water and sun. Therefore, the timber is an environmentally friendly building material compared to concrete or fired bricks. Recently in Sydney a multi-storey building has been completed. To avoid ageing the timber selected was a cross laminated plywood glued together in layers to achieve durability. The cross laminated timber was developed in Switzerland in the 1970’s. This technique of cross lamination is expensive and only suitable for those with deep pockets. A new multi-story building with cross laminated timber construction is proposed for Sydney for the Atlassian Software Group who certainly appear to have deep pockets.
For standard timber building methods one of the drawbacks is that the timber in place absorbs water and commences ageing. This ageing comprises wetting and drying and subsequent cracking and colour changes such as darkening and rotting or growth on the timber surface of biological material. As time progresses the deterioration of the timber can be substantial until replacement of at least part of the structure is necessary. If the timber is painted with a surface coating then the attractive appearance of natural timber disappears and this defeats the purpose of presenting a natural look. Of course, the timber may be painted with a lacquer type of product either matte or gloss however this also negates the natural appearance of the timber. In addition, on weathering the surface coating may delaminate and require expensive surface preparation and re-treatment which is expensive particularly for multi-storey structures.
There is an entire industry of in plant treatment of timber to make it durable and there exists a plant in the Netherlands where at high temperature the timber undergoes a reaction of acetylation and this produces a durable but very expensive product. The treatment of the timber with such chemicals in many ways negates the desirability of natural materials.
Aware of these problems, scientists at Tech-Dry worked on water repellents for timber to increase the lifetime of the outdoor timber. The parameters under which the scientists operated were to achieve no waste in the manufacture of the water repellent and no significant loss of volatile organic compounds to the atmosphere which would cause in situ pollution. After years of research and development a silicone water repellent was finally produced which penetrates the surface of the timber and causes water to shed from the surface and remain essentially dry and be to all intents and purposes waterproof. This treatment is markedly superior to acrylic-based surface finishes which are coatings which may peel and deteriorate in sunlight. This product Tech-Dry Timber Water Repellent is water-based, environmentally friendly, easy to apply and economic to treat timber surfaces.