Question: What are the differences between "pre-built", "pre-cut", "outdoor" and "portable" traditional saunas?
Answer:

Pre-Built (Modular) Saunas come in modular insulated panels that are assembled together to form a fully functional room.

Pre-Cut Sauna Kits require that you frame up your own walls and provide your own insulation. Tongue and Groove boards from the kit are provided to attached to the inside framing of your room.

Outdoor Traditional Saunas are exactly like a pre-built's in addition to having a roof package option.

Portable Traditional Saunas are small modular rooms that are capable of plugging into standard wall outlets (15amp or 20amp).

Question: How thick is the tongue & groove boards in an Avalon pre-cut sauna kit?
Answer: The 1" x 4" T&G boards in the Avalon Pre-Cut sauna kits have an actual thickness of 11/16". This is thicker than the standard within the industry of ½" thickness.

Question: What heater upgrade options do I have with the Avalon Pre-cut Sauna Kit?
Answer: The Avalon Pre-cut Sauna Kit comes from the same manufacturer of the Catalina Pre-cut Sauna Kit therefore giving the option to upgrade to a Catalina brand heater or simply staying with the quality Avalon brand heater options. Both brands provide the user a true sauna experience with a slightly different design.

Question: What is the advantage of the ¾" thick T&G included in the Avalon Pre-cut Sauna kit?
Answer: The ¾" (Actual Thickness 11/16") will provide a little better R Value, it has less chance of cupping and warping over time, and you have a wider shoulder & tongue to shoot the nail through.