Spruce Wood (Cladding and Structure)

Spruce wood is a softwood species commonly used in Central and Northern Europe for wall cladding, structural elements and exterior decking on saunas and pergolas. Spruce has a light colour, a straight grain and a lower density, which makes it easier to work and reduces structural weight. In its raw state it has higher thermal conductivity and greater sensitivity to moisture than species intended for direct skin contact, so within a sauna interior it is used mainly for walls and ceilings. Siberian larch, a related species with a higher resin density, is instead often chosen for exterior decking because of its natural durability. Standard spruce intended for outdoor use is therefore usually combined with heat treatment or a protective coating.

Advantages of spruce wood

• Low cost and good availability: Spruce is among the most widely available construction timbers in Central Europe.
• Low structural weight: Lower wood density simplifies handling and reduces the load on the supporting structure.
• Straight grain: The uniform, light appearance combines well with a minimalist interior design.
• Suitability for heat treatment: Spruce responds well to thermal treatment, which significantly increases its durability for outdoor use.