Thermo-Spruce Sauna Wood

Thermo-Spruce is spruce thermally modified by ProSaunas with heat, steam and pressure and no chemicals. ProSaunas describes a smooth, refined finish, a rich amber color and a highly figured, knotty look; it is sold here as paneling and bench wood in lengths from 1 ft up to 10 ft.

Thermo-Spruce paneling and bench wood

Paneling: 1x4 STS4 nickel gap.
Bench wood: 2x4 and 2x6.

There is no Thermo-Spruce trim. For corners and the door frame, sauna trim comes in Thermo-Aspen and Thermo-Radiata Pine, the two other thermally modified woods. Apart from the thermal treatment the boards are unfinished.

Thermo-Spruce sauna wood next steps

Comparing woods: every species, paneling profile and bench size is on the sauna wood page.
Planning the room: doors, windows and lighting are in sauna building materials.
Not sure how much to order: send your room size to Topture's Lifetime Expert Support.

Reviewed October 2026

Frequently Asked Questions

What is Thermo-Spruce?

It is spruce that ProSaunas thermally modifies with heat, steam and pressure and no chemicals. ProSaunas describes a smooth, refined finish, a rich amber color and a highly figured, knotty look.

Is there Thermo-Spruce trim?

No. Thermo-Spruce comes as 1x4 nickel-gap paneling and 2x4 or 2x6 bench wood; trim is available in Thermo-Aspen and Thermo-Radiata Pine.

How is sauna wood shipped?

Sauna wood ships to the contiguous US at one flat freight rate per order, set by the number of boards across all the sauna wood in the cart and the length of the longest board. The rate table is in the Shipping tab on every sauna wood page. Boards over 10 ft and orders of 1,000 boards or more are quoted after you order.