Have you ever dreamed of having your own Finnish Sauna Room right in your own home? It might be easier than you think. With a little research, a touch of carpentry experience and some good old fashioned hard work, you can create a safe and wonderful sauna experience right in your own home.
With a little help from this sauna installation guide, you can be sure to build a safe and efficient sauna room for you and your family.
As you search your home for the perfect location for your sauna room, you may find that you have a closet or un-used room in that basement area that you want to convert into a sauna room. This will save you the time and energy of custom framing the walls of your sauna.
Most sauna buyers will buy a package that will include everything needed to complete your sauna room. The sauna kit should include the following: foil vapor barrier, wall and ceiling boards, bench lumber, corner molding, air vents, sauna door, sauna light, wood or vinyl flooring, sauna heater with control and rocks, thermometer, bucket and ladle.
When buying a “pre-cut” sauna room, always ensure that you order a room that is no smaller than the stud-to-stud wall and ceiling dimensions. An exact fit is always nice, but if you are unsure of the exact measurements, always buy the next size larger and cut the room to fit on site.
The first question you may have asked yourself is “How long will it take me to build the sauna room”? We typically recommend 2 – 3 days of hammer in hand build time for a 2-person team.
Of course, this time can be longer based on experience as well as the size and details of the sauna room. This also does not include the time needed to plan the project, get the construction materials on site, roughing-in the electric and insulation and don’t forget final clean up.
Once you have the room picked out you will want to insulate the walls and ceiling. We recommend using a fiberglass insulation with an R13 rating in the walls and an R19 rating for the ceiling. As an alternative to the messy and uncomfortable fiberglass batting, you may want to consider using an all-natural, environmentally friendly cotton insulation. It is primarily made from cotton blue jeans and is slightly more expensive than typical insulation.
After the insulation is in place you will need to staple a foil vapor barrier to the studs of the sauna room. This will prevent water vapor from penetrating the fiberglass and wall cavities and to reflect and radiate the heat back into the sauna room to better maintain and regulate the heat inside of the sauna room and prevent the risk of fire. Overlap the seams 6” and extend
the foil vapor barrier to cover the ceiling joists. Use all temperature aluminum duct tape to cover all the seams and any accidental tears or penetrations.
Now we can proceed to the installation of the ceiling and wall boards. You have your choice of woods to cover the walls and ceiling. The most popular sauna wood is 4” tongue and groove Cedar wood. Its light weight, straight grain and durability makes it an excellent choice for sauna room construction. As an alternative to Cedar wood, you could consider Hemlock. Hemlock is a great alternative as it has a very consistent light color without the plicatic acids found in Cedar wood which can be a severe allergen to some sauna bathers.
When installing the ceiling and wall boards, we recommend using a compressed air nail gun or an electric nail gun with 1 1/8” galvanized nails. If the nails don’t fully compress into the tongue, you may need to follow up with a hammer and nail sink to ensure that the tongue and groove fit perfectly together.
Start the cedar installation by installing the tongue and groove boards across the ceiling joists. You will nail into the tongue at a 45-degree angle. Confirm that the nail heads are hidden in the tongue and are fully flush to easily receive the next grooved board.
Once the ceiling is covered you can begin the walls by nailing a level board about ½” from the floor. Proceed to “stack” the wall boards, checking for level every few rows. Note that the “grooves” will all face down to prevent water from collecting in the joints. When you come to the last wall board adjacent to the ceiling, you will find that you will need to trim the this board to fit. Remember to cut about ¼” short so that you have room to maneuver the board in to place. Any remaining gaps in the corners will be covered by 1x1” corner moulding which should be installed after the benches are in place.
A top tip is to mark the surface boards to note the location of the bench and heater supports. Failure to perform this easy task will result in you hunting for the anchor points later in the project.
Next, we move on to building and installing the sauna room benching. A popular configuration is to install an upper and lower bench. This gives the bather the choice of temperature to enjoy. As the heat rises in the room the upper bench will be in the “heat” zone. The lower bench will be a bit cooler for those with a desire for a lower sauna temperature.
Most residential sauna benches are constructed of a 2x4” cedar frame with 1x4” cedar top boards. Commercial sauna benching is usually made entirely out of 2x4” cedar boards for the frame as well as the top boards. It is critical to use only clear, tight grained, sanded, knot free wood for the construction of the sauna benches. This is not the place to cut corners on wood quality.
Install the bench supports to the sauna room walls and measure the exact length of each bench wall. Often, you will find the walls are not square and the benching will need minor adjustments. It is best to find this out prior to building the benching to ensure a tight, custom fit. Once constructed, the benches are set in to place and attached to the leg and wall supports.
The final steps to finish your sauna room are to mount the sauna rated door, install the vent covers, connect the sauna rated lighting and make final connections to your sauna heater, thermostat and control per the manufacturers instructions.
