The Wood That Withstands the Heat: Choosing the Best Lumber for Your Sauna

Building a custom sauna requires specific lumber selection. In this high-heat, high-humidity environment, the wrong wood can bleed sap, retain heat (making benches too hot to sit on), or even warp and rot quickly. The best lumber is low-density, low-resin, and resistant to moisture.

Western Red Cedar: The Gold Standard

Western Red Cedar is the industry leader for sauna construction. Its key benefits include:

• Low Density: Cedar is soft and light, meaning it absorbs less heat than dense woods. Benches and walls remain cooler to the touch.

• Aromatic Properties: It releases a mild, pleasant aroma when heated, enhancing the spa experience.

• Decay Resistance: Its natural oils make it highly resistant to the moisture and fungal growth common in saunas.

We recommend clear-grade cedar for interior use to minimize knots and create a smooth, luxurious finish.

The Resin Factor and Lumber Profiles

Avoid high-resin woods like most varieties of Pine or Fir; the heat will cause sap to ooze out, creating sticky, hot, and messy surfaces.

For the best insulation and longevity, always choose tongue-and-groove (T&G) lumber for your sauna walls and ceiling. T&G lumber creates a seamless, interlocking fit, which minimizes heat loss and prevents moisture from penetrating the wall cavity.