Thermal modification is a specialized process where wood is heated (using steam) to a very high temperature to transform it on a molecular level into a highly-durable outdoor material. Thermal Modification turns the wood to a beautiful chocolate brown color, which indicates that the wood has reached the proper temperature (around 400-410⁰ F). At that point, the wood undergoes a fundamental change where the sugars and starches caramelize, making the wood a non-food source. Also, the wood cell walls lock into place, preventing the wood from absorbing water like that of unmodified wood. Overall, the durability of the wood is multiplied many times, giving Thermally Modified wood a 25+ year lifespan outdoors without chemicals or anything else manmade. The primary purpose of Thermal Modification is durability (resistance to rot, increased lifespan, resistance to insect damage). Thermal Modification gives the wood Class 1 durability (25+ years).