Wooden hot tubs are being produced from the certified kiln-dried pinewood or thermo-wood, with the wall thickness of 46 mm. Pinewood is accurately sawn, kilned and graded according to wood features. Thermo-wood is produced by using high temperature and steam. No chemicals are added during the process; therefore it is ecological and environmental friendly choice. Also the dimensional stability, biological durability and insulation properties of the wood are improved.