With architects turning their attention to timber as a favourite material for cladding, Steve Grimwood, Managing Director of OrganoWood®, the natural wood preservative specialist, explains the necessity for specifying a wood protection that offers more than just an aesthetically pleasing finish.
Timber has always been a popular cladding material in many countries throughout Europe. This is due to timber offering a unique combination of both aesthetic and practical features. As a strong, reliable and attractive material, timber is a sought after choice from architects and end users, for both residential and commercial cladding applications.
As with any natural material, wood requires treatment to provide sufficient protection to maintain its appearance and structure, and maximise the material’s potential.
The Timber Decking and Cladding Association (TDCA) recommends the use of industrial wood protection processes to enhance the long term performance of timber that lacks adequate natural durability. The association reminds the industry that ‘the sapwood of all species is not durable and needs protection.’
For architects selecting a finish, it is important to ensure that the product will provide the right level of protection, as well as an aesthetically pleasing end result.
Various manufacturers, including OrganoWood, are offering a new generation of wood protection. A tried and tested ecological alternative to pressure treated finishes, these products are both aesthetically pleasing and sustainable, and offer flame, rot and fungal protection, as well as extreme water and dirt repellence.
Through proprietary technology, which mimics the natural fossilisation process, the timber is modified by the attachment of protective silicon compounds to the wood fibres.
Rot and Flame Protection
Where building regulations require fire performance in accordance with British Standards or Euroclass, the TDCA recommends pre-treatment with a quality assured flame retardant.
Unlike traditional timber protection systems, which rely on biocides to kill the rot fungi and other timber destructive organisms, this new generation of wood protection uses no substances classified as hazardous or harmful, but only natural minerals and fruit substances. These products are tested to meet all relevant European environmental and performance standards and have received EN113 and EN 13501-1 certification for rot and fire protection respectively.
Dirt and Water Repellent
The TDCA also highly recommends the use of moisture permeable coatings.
As wood is not naturally as resistant to water, dirt and stains than other materials, it is important for architects to specify a treatment that will add durability. For cladding installations, measures should be taken in order to protect the timber from water. Structurally, the wood can be designed to allow the water to drain off easily, but a water repellent treatment will reduce the risk of stagnant moisture marking and absorbing. Without treatment, the wood is prone to decay and is likely to warp out of shape. Fungi and mould are also more likely to develop, so a finish that combines properties to counteract this will further increase the durability.
In the UK, architects and end users look favourably on environmentally friendly products. To get the best results from a timber finish, it is important to specify a product that is entirely non-toxic – without the use of harmful heavy metals, biocides and solvents. It is important to opt for products that are ecologically sustainable according to FSC® (FSC-C120532) and PEFC™ (05-35-168).
As well as offering a high level of protection, these finishes provide an appearance that is desired by many. The finish gradually ages with an aesthetically pleasing silver-grey hue over time.
OrganoWood offers architects a range of products that consists of OrganoWood® 01. Protection which offers rot and flame protection, OrganoWood® 02. Repellent to provide a dirt and water repellent surface and OrganoWood® 03. Cleaner, an organic wood cleaner for general and intensive cleaning and maintenance of the wood.