Reinvention of Ancient Wood Protection Technology
Of late there has been significant interest in rekindling time-honoured wood finishes, and many of them perform better than modern alternatives
Of late there has been significant interest in the rekindling of time-honoured wood finishes. Many of these surface finishes are experiencing a renaissance in a world where natural materials are increasingly desired. Surprisingly, many of them perform better than modern alternatives.
Shou Sugi Ban / Charred Wood
A Japanese art of charred wood - known as Shou Sugi Ban or Yaki Sugi - is making inroads in modern architecture. It’s believed that the finishing techniques Asian roots date back to the eighteenth century, when the Japanese first started charring wood siding with fire as a way to preserve it. After charring, the wood is sealed with natural oils.
Over time, the surface of wood erodes when exposed to ultra violet rays, wind and moisture. By creating a deep char, it is possible to protect timber from sun, wind, water, decay and fire, significantly extending its life.
Charring wood improves the fire resistance of timber. When the surface of wood is burned, the softer, more reactive cellulose vaporises and gets burned off, while harder lignin takes a longer time to burn. The residual blackened lignin requires much higher temperatures and a longer time in contact with a flame source to reignite.
It is critical to have as stable, chemical free timber for charring. Abodo’s Vulcan Cladding provides the perfect substrate, with high stability and natural durability. Examples of charred wood projects include the award winning Lake Waikaremoana Welcome Centre.
Iron Vitriol / Iron Sulphate
Iron sulphate has been used for generations as a surface treatment to create the impression of a weathered wooden façade that has turned grey. Iron sulphate reacts with tannins in wood and causes a chemical colouring on the surface of the timber.
Iron sulphate is generally mixed with water and is a colourless liquid that is painted or sprayed onto the sawn face of new wood or wood previously treated with iron sulphate. Over time, treatment with an iron sulphate solution turns the timbers surface an attractive and lasting brown-grey to silver-grey colour, depending on the species of timber used. The wood should be treated before being installed, as this gives better penetration on the tongues and grooves.
One of the benefits of iron sulphate is that it “self-healing”, generally cracks and damage to wood will be naturally resealed by the stain.
Iron sulphate is low toxicity and generally does not contain volatile organic compounds (VOC’s)
Abodo’s Tundra and Vulcan are excellent substrates for iron surface based treatments. The strong tannins in Tundra react quickly with the iron forming a dark brown black colour quickly. The reaction with Vulcan is more sedate, with a long lasting deep chocolate brown.
Silicate technology to protect and preserve wood was developed in Germany in the 19th century; old methods can be surprisingly efficient. It has found widespread use in applications such as decking, terracing, and cladding. The surface develops a pleasing silver-grey nuance
Layers of silicate crystals grow deep in the wood, providing a barrier and a resistive protection against fungus, vermin and microorganisms trying to gain a hold
Modern versions of silicate based wood coatings now perform better. While older methods relied on large silicate molecules, the ones used in Abodo’s Sioo:x coating are smaller. We have also substituted sodium as a helping agent, for potassium. The advantage of the Sioo:x solution is that it quickly penetrates the wood and combines with it.
Abodo is at the forefront of modernized ancient wood protection techniques.
Contact the Abodo team to discuss finish options.