How to Season a New Sauna: Breaking In Your Sauna the Right Way

How to Season a New Sauna: Breaking In Your Sauna the Right Way

Your sauna is built, the heater is connected, and you're ready to hop in. Not so fast. A brand-new sauna needs to be seasoned before your first real session. Seasoning burns off manufacturing residues, acclimates the wood to heat, and gets the heater stones properly cured.

Skip this step and your first session might smell like chemicals, heated adhesive, and burnt dust instead of warm cedar. It takes a few hours, but it's worth doing right.

Why Seasoning Matters

New saunas come with residues from the manufacturing and assembly process:

• Wood oils and resins. Even kiln-dried and heat-treated wood releases some volatile compounds when first heated. These need to be burned off before you breathe them in.
• Heater element coatings. New electric heaters often have a protective coating on the elements that produces smoke and smell on first heating.
• Sauna stone dust. New stones are dusty from shipping and handling. The first few heat cycles burn off surface dust and impurities.
• Adhesive and sealant off-gassing. Any adhesives used in assembly release compounds when first heated. Better to let these burn off in an empty sauna.
• Sawdust and debris. Construction dust from cutting, drilling, and assembly settles on every surface and needs to be cleared before you sit on it.

Before You Start: Prep the Sauna

1. Clean everything. Sweep or vacuum the floor, benches, and walls. Wipe down all surfaces with a damp cloth to remove sawdust and debris.
2. Check the heater installation. Make sure the heater is properly mounted, wired, and that all stones are loaded per the manufacturer's instructions. Stones should be loosely stacked with air gaps - not packed tight.
3. Check ventilation. Make sure your intake and exhaust vents are open. You want maximum airflow during seasoning to carry out odors and residues.
4. Remove anything that shouldn't be heated. Buckets, ladles, thermometers with plastic components, and any packaging or assembly materials should be taken out.

The Seasoning Process: Step by Step

Session 1: Low Heat (30 Minutes)

1. Turn the heater to its lowest setting (around 120-140F).
2. Let it run for 30 minutes.
3. You'll likely smell some off-gassing - a slightly chemical or "new" smell. This is normal.
4. Turn off the heater and let the sauna cool completely with the door cracked open for ventilation.

Session 2: Medium Heat (45 Minutes)

1. After the sauna has cooled, turn the heater to a medium setting (around 150-170F).
2. Run for 45 minutes.
3. You may still notice some smell, but it should be less intense than session 1.
4. If you have a traditional heater with stones, pour a small amount of plain water on the stones. This creates steam that helps carry away surface impurities from the stones.
5. Turn off and cool with the door open.

Session 3: Full Heat (60 Minutes)

1. After cooling, bring the heater to full operating temperature (180-200F or your normal setting).
2. Run for a full 60 minutes.
3. Pour water on the stones several times to generate steam and thoroughly cure the stone surfaces.
4. By the end of this session, any chemical or "new" smell should be gone or nearly gone.
5. Let the sauna cool completely with the door open.

Session 4 (If Needed): Full Heat Repeat

If you still notice an off-smell after three sessions, run a fourth full-heat session. Some wood types (particularly certain softwoods) take longer to release all their resins. If you have a cedar sauna, you'll notice the cedar scent becomes more pleasant and natural after seasoning - the harsh "new" edge gives way to the warm cedar aroma.

Seasoning Timeline

The whole process takes a single day if you don't rush it. Plan for about 6-8 hours including cool-down periods between sessions.

Special Notes for Different Heater Types

Electric Heaters (Harvia, Huum, etc.)

Most electric heaters produce some smoke on first use from the element coating burning off. This is normal and harmless. Run the heater without anyone in the sauna for the first session. The smoke clears quickly.

Wood-Burning Stoves

The first few fires in a new wood stove produce more smoke and creosote as the metal and paint cure. Use small fires for the first 2-3 burns. Avoid roaring fires that overheat the stove before the paint and gaskets have set. Keep the chimney damper open wide during seasoning.

After Seasoning: Your First Real Session

Once the sauna smells clean and natural:

1. Do a final wipe-down of all benches and surfaces.
2. Place your thermometer/hygrometer inside.
3. Set out your bucket, ladle, and any accessories.
4. Fire it up to your preferred temperature.
5. Lay down a towel on the bench and enjoy your first real session.

Tips for the First Few Weeks

• Wood movement is normal. New wood expands and contracts as it adjusts to heat cycling. You may hear creaking or popping sounds during the first few sessions. Small gaps may appear between boards and then close up. This is completely normal and usually stabilizes within a few weeks.
• Resin spots may appear. Some softwoods develop small resin beads on the surface during the first few high-heat sessions. Let them harden, then scrape off gently with a putty knife and sand smooth.
• Tighten barrel bands. If you have a barrel sauna, check and tighten the metal bands after the first week of regular use. The heat cycling causes the wood to settle, and the bands may need adjustment.
• Check hardware. Screws and bolts may loosen slightly as wood moves during the first heat cycles. Retighten bench screws, door hinges, and any visible hardware after the first few sessions.

Browse our outdoor sauna and indoor sauna collections. All SweatDecks saunas ship with premium Harvia or Huum heaters and FSC-certified heat-treated Canadian hemlock that's pre-seasoned for minimal off-gassing. For ongoing care, check our sauna maintenance guide.