Thermal Poplar 2 inch Bench & Floor BoardsMade from Carbon Smart Wood premium thermally modified or naturally durable lumber from Cambium Carbon's nationwide salvage and milling network. About Thermal Poplar Thermal Poplar is North American yellow poplar transformed through a high temperature thermal modification process. The wood is heated to 380430F in an oxygen controlled chamber, fundamentally changing its cell structure. The result: a rot and decay resistant softwood with dramatically