Maintenance Guides
Backyard Sauna Maintenance Guide
Updated January 2025 · 10 min read
A well-built sauna can last 40 years. Some last longer. The ones that don't? They were neglected — wrong cleaner on the wood, standing water under the floor, door seals left to rot. None of it is hard to prevent. Takes maybe 30 minutes a month. Here's the whole system.
🗓️ Maintenance at a Glance
After Every Use
Air it out, wipe benches, leave door cracked
Monthly
Clean interior, inspect door seal, check rocks
Annually
Sand/treat benches, inspect exterior, replace rocks
After Every Session
Leave the door cracked open
For 30–60 minutes after your session. This lets moisture escape instead of soaking into the wood. The single most important habit for sauna longevity.
Wipe down the benches
A quick pass with a dry towel removes sweat before it soaks in. Cedar is naturally antimicrobial but it's not bulletproof.
Empty the water bucket
Don't leave water sitting in the bucket — it breeds bacteria and leaves mineral deposits.
Turn off the heater
Obvious, but worth saying. Use a timer outlet if you're forgetful.
Monthly Maintenance
Deep clean the interior
Use a sauna-specific wood cleaner (not bleach or household cleaners — they damage cedar). Scrub benches with a soft brush, rinse lightly, air dry with door open.
Inspect the door seal
Press around the door frame when the sauna is hot. If you feel heat escaping, the seal is failing. Replace weatherstripping before it causes heat loss and higher electricity bills.
Check sauna stones
Look for cracked or crumbling rocks. Degraded rocks don't hold heat and can become projectiles when water hits them. Replace any that look compromised.
Inspect exterior wood
Look for cracking, graying, or soft spots. Catch rot early — it's cheap to treat a small spot, expensive to replace boards.
Annual Maintenance
Sand and treat the benches
Once a year, lightly sand the bench surfaces (120-grit) to remove gray patina and raised grain. Apply a food-safe sauna wood oil or leave untreated — never use polyurethane or varnish on sauna interior wood.
Replace sauna stones
Every 2–3 years (sooner if they're crumbling). New stones hold heat better and are safer.
Treat exterior wood
Apply an exterior wood stain or penetrating oil to the outside of the sauna. This protects against UV, moisture, and rot. Do this every 1–3 years depending on your climate.
Inspect electrical connections
Have an electrician check connections at the heater terminal block every 2–3 years. Heat and humidity cause terminal oxidation that can create fire hazards.
Check the foundation
Walk the perimeter. Any shifting, settling, or water pooling under the sauna should be addressed before it worsens.
Winter Prep (Cold Climate)
Traditional cedar saunas don't need to be "winterized" — they handle cold fine. But a few habits help:
- After the last fall session, do a thorough clean and leave to fully dry before it freezes
- Inspect and replace door seals before winter — cold air infiltration is worse with failing seals
- For barrel saunas, clear snow off the top after heavy accumulation (though the barrel shape sheds most of it)
- Don't leave the sauna unheated for months then blast it immediately — heat it gradually the first time in spring
Recommended Maintenance Products
Sauna Wood Cleaner & Protector
pH-neutral, sauna-safe cleaner that cleans and conditions cedar benches without harsh chemicals. Use monthly.
~~$28 on Amazon
Check Price on Amazon →Need Accessories Too?
See our guide to the best sauna accessories — including cleaning supplies, buckets, and thermometers.
Best Sauna Accessories →