Assembly of the Solid Log saunas is easy. Logs are held together at the corners with the aluminum corner profile. Heat retainment of the log wall is high. The groove in the bottom, and a notch at the top of the log create a thermal lock in the joints. There is no need for further insulation. The log walls are reinforced with threaded bars that run vertically inside the wall. Once assembled, the sauna is so steardy that it can even withstand an earthquake. The Solid Log sauna comes with a stainless steel electric heater, but can be optionally fitted with the Tornado™ woodburning heater.