Thermowood is produced by heat treating selected Scandinavian Redwood that is conditioned in a unique continuous kilning process, heating the timber to 212 Celsius whilst protecting it with steam. This thermal process enhances the chemical and physical properties of the timber providing many benefits the main one being increasing the durability of the timber from class 4 to class 2 as detailed in BS 8417. It is a very stable product and on average is 40% more stable than a non modified redwood and if left untreated, when exposed to rain and sunlight, it will go an attractive silver grey colour.