How to Build a Small Infared Sauna

Determine the location of the sauna. If you want an outdoor sauna, check into building codes for your area. Building an indoor sauna is oftentimes easier, since you can use already existing walls for part of the sauna.

Determine the room size and design a layout for the room. For one individual, a sauna measuring 3 1/2 by 3 1/2 feet should be adequate; for two people, 4 by 4 feet; and for four people, 4 by 6 feet. The more people, the larger the size of the room.

Sketch a preliminary layout to determine the placement of the door, the benches, the heaters and the light. Keep the ceiling of your sauna relatively low; otherwise, heat will escape more easily.

Determine how many heat emitters will be necessary for your sauna. Determine how many cubic feet your sauna measures by multiplying the length of the sauna by the width of the sauna by the height. You should have 17 watts of energy given off for every cubic foot, so multiply your total cubic footage by 17 watts to determine total wattage. Then divide the total wattage by 163 to see how many emitters will be needed. Emitters come in sets of two, so divide your final number by 2 to figure out how many sets you will need. If you come up with an odd number, round the number up. It's better to have too many emitters than not enough.

Build the walls. Most saunas are built using 2-by-4 lumber spaced 16 inches on center. You want to ensure a tight fit with sauna walls, so tongue-and-groove boards are recommended since they can contract and expand with the heat.

Avoid using dry woods like oak, since they have a tendency to split. Waterproof walls aren't necessary either, since infrared saunas do not use water. Whatever type of wood you choose, leave it unfinished. Finished wood will release toxins once heat is applied.

Make sure walls are properly anchored and sturdy. If you are unfamiliar with this type of construction, ask for help from a trained carpenter.

Install the door. The easiest way to do this is to purchase a prehung door. Make sure the space left for the door is large enough to accommodate a prehung door. The width of the rough opening should be 2 inches larger than the door itself. The height of the opening should be an inch taller than the door so the door jamb can easily fit within the space provided. For infrared saunas, an insulated door is not necessary, although it is more energy efficient.

Provide ventilation space. For a sauna to work properly, air circulation is key. Leave some space at the door threshold to allow fresh air to flow inside. Outgoing air vents should also be built into the opposite wall about two-thirds of the way up.

Build your floor and ceiling. Unlike steam saunas, a duck board is not necessary for the floor since there is no water to worry about. However, use fire-resistant material. Also keep the ceiling relatively low to prevent air from escaping.

Build your benches. Use the same wood you used for the walls to build them. Traditionally, sauna benches generally extend the length of the sauna room and measure about 2 feet wide. When installing the benches, heads of nails and screws should be recessed into the wood. Otherwise, you or your sauna guest could get burned by the heated metal.

Install a light fixture. The location, design and number are entirely up to you.

Prepare emitter units. Emitter units should come complete with a housing tray, a reflector, two ceramic emitters, two clips and two sets of nuts and screws. The housing tray and reflector unit will come as one unit. You will have to separate them before installation.

Install the emitters. If you are unfamiliar with electrical procedures, call an electrician to complete the process. The emitter wires must be threaded through the hole in the reflector. The emitter will then need to be attached to the reflector by sliding the clips into the grooves provided. Put the emitter wires into the terminal blocks and then screw the unit down to secure. Reattach the entire unit to the housing tray.

Place the emitters where desired. If the emitters are placed above the benches, position them vertically. If they are placed under the benches, position them horizontally. It's a good idea to place place them in a recessed portion of the wall with a wire grid over the emitter, so no one can touch it directly when in the sauna.

Install emitter units. They should be placed with fire-resistant insulation behind each emitter. Then hook them up to the main power source. Ask an electrician for assistance.

Install sauna controls. No matter what type of controls you purchase, typically there will be installation to do both on the inside and the outside of the sauna. Follow the directions that come with the controls and ask an electrician for further assistance.