Can You Put a Sauna on the Second Floor?

Can You Put a Sauna on the Second Floor?

You absolutely can, and plenty of homeowners do. But there is a catch: you need to make sure your floor can handle the weight, and you need to deal with moisture so it does not end up dripping into the room below.

Let's walk through what matters before you commit to an upstairs sauna.

How Much Does a Sauna Weigh?

This is the first question, and it matters more than most people realize. A small two-person indoor sauna typically weighs between 400 and 800 pounds once assembled. Larger four-to-six person units can push 1,200 pounds or more. Add the weight of the people inside and the heater, and you are looking at a significant load concentrated in a relatively small area.

Standard residential floors are built to hold about 40 pounds per square foot. A small sauna with a 4x6 footprint spread across 24 square feet has a structural budget of roughly 960 pounds. That works for most compact saunas, but it gets tight with bigger models.

Check Your Floor Joists First

Before buying anything, look at your floor structure. If you can access the joists from below (through a first-floor ceiling or basement), check the joist size and spacing. Standard 2x10 joists spaced 16 inches apart can generally handle a small-to-medium indoor sauna without reinforcement.

If your joists are 2x8 or spaced 24 inches apart, you will likely need to add support. A structural engineer can evaluate your specific situation for a few hundred dollars, and that peace of mind is well worth it.

Common reinforcement options include:

• Sistering joists - Adding new joists alongside existing ones to double the load capacity
• Adding a beam below - Running a support beam perpendicular to the joists under the sauna location
• Blocking between joists - Installing solid blocking to distribute the load across multiple joists

Waterproofing Is Not Optional

When a sauna sits on a concrete slab or an outdoor surface, moisture just drains away. On a second floor, any moisture that escapes the sauna can seep into the subfloor and damage the ceiling below. This is the number one concern with upstairs sauna installations.

At minimum, you should:

• Install a waterproof membrane or shower pan liner beneath the sauna
• Seal the subfloor with a moisture barrier before placing the sauna
• Make sure the sauna has a proper vapor barrier on its walls and ceiling
• Consider a drain in the floor if you plan to use water on the sauna stones

Many homeowners skip the drain and simply keep water use minimal. If you stick with dry sauna sessions, the moisture concern drops significantly.

Which Sauna Types Work Best Upstairs?

Not all saunas are created equal when it comes to second-floor installation. Here is how the options stack up:

• Infrared saunas - These are the easiest choice for upstairs. They are lighter, produce no steam, plug into standard outlets, and generate minimal moisture. If weight and moisture are your main concerns, infrared is the simplest path.
• Electric Finnish saunas - These work well upstairs too, but you will need a 240V circuit and more attention to waterproofing since steam is part of the experience.
• Traditional wood-burning saunas - Not practical for a second floor. The chimney requirements and fire code restrictions make this a non-starter in most homes.

Browse our indoor sauna collection to see models that work well for upstairs placement.

Ventilation Matters More Upstairs

Every sauna needs proper ventilation, but it is especially important on a second floor where heat and moisture have nowhere to go but into your living space. Plan for a lower intake vent near the heater and an upper exhaust vent on the opposite wall. The exhaust should vent to the exterior of the house, not just into the room or attic.

If exterior venting is not possible, at minimum open a window in the room after each session to let moisture escape before it settles into walls or flooring.

Electrical and Permits

A 240V electric sauna heater needs a dedicated circuit with the correct amperage breaker. Running this to a second floor typically means routing wiring through walls from the main panel. Hire a licensed electrician - this is not a DIY wiring job.

Some municipalities require a building permit for indoor sauna installations, especially if you are modifying the electrical system or floor structure. Check with your local building department before starting work. The permit process is usually straightforward and protects you when it is time to sell the house.

Bottom Line

A second-floor sauna is completely doable if you respect the weight limits and handle moisture properly. Get your floor structure evaluated, waterproof thoroughly, choose an appropriate sauna type, and ventilate well. Thousands of homeowners enjoy upstairs saunas without any issues - it just takes a little more planning than a ground-floor install.

Ready to find the right fit? Check out our indoor saunas for models that work great on upper floors.