If you recently purchased an outdoor sauna, or wish to buy one soon, you may be wondering if you need insulation. To make the process easy, you should get an idea of what insulation is and how it works in regard to sauna use.  You should also understand when you need insulation when you do not, and how to install it if needed. Here is more information on if your small outdoor sauna needs insulation. 

WHAT IS INSULATION?

According to The Department of Energy, insulation provides resistance to heat flow. During this process, heat travels and changes from a warm to a cooler temperature. Most insulation types work in one of two ways:

1. Conductive heat flow slows down.
2. Radiant heat gain reduces using radiant barriers or reflective insulation.

The process ends when the difference in temperature goes away.

DO SMALL OUTDOOR SAUNAS NEED INSULATION?

Sources prove that putting insulation in your sauna will have its share of perks. Certain sauna types do not need it. Here is a deeper look at the reasons why you should opt to use insulation.  

BENEFITS OF USING INSULATION IN YOUR SMALL SAUNA

AUTHENTIC SAUNA FEEL

A vapor barrier with the right sealing and insulation makes the sauna feel more solid. It gives a more realistic session.  Many sauna fans like the traditional outdoor sauna better. They also share the same sentiments about using a sauna with a solid wall structure.

MOISTURE WILL NOT LEAK

• Scientifically, warm, wet air rushes to cool, dry air.
• When hot rooms are not sealed, the warm, wet air sticks to the wood paneling, which is cooler in temperature.
• Actively combating the condensation is best for your sauna wood treatment.

HOLDS HEAT INSIDE

• An insulated sauna reaches high temperatures at a quicker rate.
• The correct vapor barrier and insulation both hold heat inside the sauna.
• Trying to warm a non-insulated sauna is like trying to bake a cake while the oven door is still open.

WHEN INSULATION IS NOT REQUIRED FOR YOUR SMALL SAUNA

If you are building your own outdoor sauna, of course, the general idea of using insulation is a wise one. At the same time, with lots of pre-built saunas, barrel saunas to be exact, it is not required. Here are 6 reasons why your barrel saunas can do without the extra layers:

1. The types of wood used for construction, such as Red Cedar, work well for natural resistance to harsh outdoor elements
2. Wooden staves do not conduct much heat. (Cannot feel the heat outside of sauna when running)
3. Because of its radius and the circular design, the barrel sauna is ideal for optimal heat circulation.
4. No rain or snow gets stuck on the top of the sauna due to its round shape.
5. The sauna does not need to keep heat when not in use, eliminating the need for the use of insulation.
6. Operation costs do not increase when insulation is absent.

TIPS FOR INSTALLING INSULATION IN YOUR SMALL OUTDOOR SAUNA 

If you have come to the conclusion that you wish to go ahead and install insulation, be sure that you follow the correct procedures for safety and efficiency. Keep the following points in mind:

FLOOR INSULATION

• Be sure that your chosen rigid insulation can withstand being outdoors.
• Try using a polystyrene foam board with a featured thickness of 50 millimeters. Use it between the timber and the foundation.  Example: Owens Corning FOAMULAR brand 
• You have 2 options for holding it into place:

1. Use nailed woodblocks.
2. Use galvanized nails in areas that need extra support, about 2 inches from the top of the joist. 

FIBERGLASS INSULATION

• If you use fiberglass insulation for the walls, make sure that it is not wrapped in plastic. You also want to avoid it if it has a craft paper backing.
• Craft paper-backed insulation + craft paper-backed aluminum = moisture trapping from too many layers
• Begin roughing your wiring during this process. Do this so you will not have to ruin your vapor barrier by running cables behind.
• Fiberglass insulation can be very dangerous:

                Sheds harmful glass splinters

• Requires you to cover your entire body
• Recycled cotton insulation is much safer to use. You can make it using old, ripped jeans.
• For the wall, use standard 4-inch (R-13)  insulation.

CEILING INSULATION

• For the ceiling, paper-backed fiberglass is sufficient. (R-19 value/ 6-inch batts)
• You will need about two 39 foot rolls to cover both the ceiling and extra space. (i.e.: changing room) 
• Installing insulation in the entryway or storage areas is unnecessary.

FOIL VAPOR BARRIER

• Serves 2 purposes:

1. Keeps water vapors from the wall studs and insulation
2. Causes heat to reflect back into the sauna

• Paperless foil is thicker and easier to manage than a foil with craft paper backing.
• Use a staple gun to begin installation at the floor level.
• Make sure that the higher sheets lap onto the lower ones.
• Cut into wall-sized sections to make handling the sheets easier. 
• Be sure that you seal your seams with high-temperature aluminum tape.

SUMMARY

In short, unless your small outdoor sauna is a barrel-style sauna, you will need insulation. This process stops heat from flowing too much. It works by either slowing the speed that heat comes out, or slowing the rate of heat gain. Insulation stops moisture from getting inside and keeps heat inside. Barrel saunas do not need insulation because they handle the weather well.

They have wooden staves that do not let off too much heat. Their design allows heat to flow with ease. When your sauna is off, heat does not stay inside. Luckily, the cost of using your barrel sauna stays are the same without insulation. Remember that recycled cotton insulation is safer than fiberglass. Use a foil vapor barrier for keeping wall studs and insulation safe from water and heat.

For more tips on insulation, or more information on thebarrel sauna,use My Sauna World for updates.