The biggest drawback to vertical construction and it’s really pretty minor is that you’ll have to install horizontal strapping every foot (30 cm) around the framed 2×4 walls so that you have something to attach the boards to. If you want to gain an inch around the inside perimeter, you can opt to install horizontal blocks between the studs instead. Of course, this is not an issue with prefabricated saunas, which include the walls already assembled.
How will the heater be installed? Your heater must be sized to accommodate the cubic footage of your sauna. Some wall heaters are small and lightweight enough to be attached directly to the tongue-and-groove boards. Heavier units with a large rock capacity need to be mounted to the studs behind the boards. If you have to attach the heater to the studs, be sure to plan carefully and install extra studs if necessary so you can place the heater exactly where you want it. Another option is to use a floor-standing heater.
How will the door be installed? Sauna doors should open outward from the sauna and should not be equipped with any latching
device requiring lifting or turning to exit the sauna. A good option is a roller latch that allows the door to be opened merely by pushing or leaning on it. Also, plan whether you want the door to swing to the left or the right, which will depend on your particular setup.
Will there be a light in the sauna? Lighting can make the sauna more inviting, but it must be waterproof and certified for use in a sauna. If a fixture doesn’t meet these criteria, don’t use it, no matter how much you like it. Plan to install the light away from the benches so it doesn’t interfere with bathers. Some prefabricated saunas have recessed lights under the benches or in soffits around the ceiling, which produce a soft glow.
Will you need to prep the walls and ceiling before installation? Prefabricated saunas are finished on all sides and are designed to stand alone like a piece of furniture. Precut and custom saunas, however, are attached directly to walls of your home. Note that you cannot build a sauna over existing drywall. Over time, moisture from the sauna will damage the drywall. Therefore, be sure to remove all drywall from the walls and ceiling. Make sure that there is adequate insulation between the studs, and cover the wall and ceiling completely with a foil vapor barrier, which reflects heat back into the sauna and prevents moisture from getting into the walls of your home. Though you want to prevent moisture damage and heat loss, keep in mind that a sauna should not be airtight. In fact, it’s important to have adequate ‘ventilation that continually brings fresh air into the sauna. But if you’re having difficulty maintaining your sauna’s temperature, you might be exchanging the air too quickly. Through trial and error you’ll create the perfect rate of air exchange for your specific sauna.
What type of floor surface will you use? In original outdoor Finnish saunas, the floor was dirt with maybe a few wooden planks on the ground for people to walk on as they made their way toward the benches. Today outdoor sauna designs typically include a duckboard floor. You can also install a sauna directly over concrete or a wooden deck.
For indoor saunas, the floor beneath the duckboards must be waterproof so that it can be cleaned easily and isn’t susceptible to water damage. A concrete floor (such as in the basement) works well. This can be dressed up with either duckboards or plastic draining mats. Tile is becoming increasingly popular because of its upscale look and ease of maintenance. Whatever material you choose, it should be able to stand up to the climate inside a sauna.
Should you install a drain? Your sauna does not require a drain. Most of the water poured on the rocks is turned into steam. (Note: Use only potable water, not water from a swimming pool or hot tub, which may contain corrosive chemicals and be unhealthy to breathe when it becomes aerosolized.) Any small amount of water that does land on the floor can be wiped away or left to evaporate. However, if you are building your sauna from scratch and have the budget for plumbing, you might want to consider installing a drain, which will enable you to clean your sauna more easily.
How tall will the sauna be? Remember that heat rises, so you don’t want the sauna any taller than it has to be. Seven feet (2.1 m) enables most people to stand comfortably inside while keeping most of the heat at a level where bathers sit. If you have high ceilings in your house, you can leave the space above the sauna open, use it to display art objects, or build in storage cabinets.
Is there easy access to electricity? Some small saunas can be heated with a modest 110-volt heater, but most will require special 220-volt service. Work with an electrician to determine how a 220-volt line will be run to your sauna. You might decide to relocate the sauna if your original spot is too hard to reach.
By considering these questions, you’ll be well on your way to designing the perfect sauna for you and your family. Nevertheless, you’ll definitely want to visit some sauna showrooms before making your final decision. A sauna that looks good on paper has a totally different feel when you actually get inside. By visiting a sauna dealer and testing a variety of sizes and styles, you’ll have a better idea of what you really want.
Ideally, there should be a place to relax and rehydrate between sauna innings.