There are different ways to build a sauna. The following is for the outdoor type. Start by procuring all the necessary equipment.
Required Tools and Materials
Sauna heater (you can choose from electric, gas or wood)
Wood lumber (for the floor and outer walls, use oak; for the floor and inner walls, use cider)
Use a computer program or sketch paper to draw the sauna. Decide how big you want it to be (i.e. x ft long by x ft wide). When you have the figures ready, get the necessary lumber boards. The average lumber is 2 x 4 x 8 ft long. The average plank board is 18” wide x 2” thick x 96” long.
To build a sauna, begin by cutting the lumber according to the dimensions you set. Begin with the flooring. Nail four 2 x 4s to create the frame. Cut several more 2 x 4s to be used as support. Space each one regularly. For the flooring, nail as many wood planks as required by the sauna you drew up.
Cut four other 2 x 4s to make a frame for the wall. Refer to your blueprint to get an idea of how many supporting 2 x 4s are needed. Use the wood planks to make the walls. Use the nail gun to put the walls in place.
Cut the wood planks to make the outer walls. When you build a sauna, these outer walls need to be fastened on the flooring. Use the nail gun to accomplish this task.
Install the insulation; 15-inch wide fiberglass insulation batts are ideal. The insulation R rating for the sauna walls should be 13. For the ceiling it’s 22 to 26. Put the insulation in the spaces made by the lumber used to make the frame. Fasten the cedar board over the insulation. Put the exhaust vent on the other end.
Create the roof. Cut the wood planks to the proper length. You can create the frames and supports in the manner described earlier. Nail it to the walls.
Use some of the remaining wood to build a sauna bench (or benches). After building, nail it to the sauna walls.
Install the sauna heater. If you’re going to use wood, allow 90 minutes to pass before the place is heated. You can also use gas, but be sure to test for carbon monoxide. For electric heaters, 1 kilowatt is needed per 45 cubic feet.
Use 100 volt heaters for small saunas. Use 200 volts for large saunas. You’ll also need to install an intake and exhaust vent for good airflow. The intake vent should be placed nearer the floor (close to the heater).
Tips and Warnings
Do not install the electric heater unless you know how to handle electrical components.
That’s all it takes to build a sauna. When everything is set up, you can start using it.