Wood Heated Hot Tub Diy . The square shape is ideal if you want to place it in a corner to save some space. Here’s a youtube® video showing the simplest way to make a wood fired hot tub. Diy Wood Fired Hot Tub Cost DIY WoodFired Hot Tub Diy hot tub, Hot from polamsando.blogspot.com There are really two ways to heat your wood fired hot tub; With an internal burner, and with an external burner. Find source of affordable, clear cedar boards.