Prosaunas Thermo-Spruce tongue and groove 1x4 STP profile creates an attractive surface, and is recommended for sauna walls and ceilings. Thermo-Spruce wood has a smooth refined finish and a traditional rustic charm with its characteristic rich amber color and highly figured knotty look.

Thermally modified wood is highly desirable for use in saunas. Thermal modification is a completely organic process that uses heat, steam, and pressure to physically enhance the properties of the wood. Sauna wood that is thermally modified is more dimensionally stable, more water-resistant, has an ideal moisture content, and is far superior to untreated wood for resisting decay, pests, and harmful fungi.

STP is an elegant profile that produces a refined and attractive wall surface for your sauna with its narrow grooves between broad cladding boards with rounded edges. It can be combined with other wood profiles for a contrasting appearance and to create your own unique, personalized look.

Prosaunas carefully selects only the finest wood from Northern Europe and Canada, assuring that the quality and consistency of our wood selection is the best available. Our team has more than 55 years of experience crafting premium sauna rooms across North America, and we only offer wood that meets our stringent standards. Because of our total commitment to quality, we can ensure your wood order will arrive to your satisfaction.

Wood Sizing - Nominal vs. Actual Lumber Sizes: In North America, wood sizes are given in "nominal" measurements, which is the lumber’s size when it is cut from moist logs. After shrinkage from drying and surfacing, the actual size of lumber will be less than its nominal size. Please see the diagram for actual dimensions.