|There are many different grades of wood, almost all of which
can be used for a hot tub. However, different grades of wood will have vastly different
effects on the life span, stability, durability, and comfort of the hot tub.
Various parts of a tree have different resistance to decay. The outer part of a tree, generally lighter in color, is called sap wood and is the newest growth. It has not had the necessary time to develop the necessary natural decay resistance and under no circumstances should it be used in a hot tub. Only the heartwood from the center of the tree possesses the natural decay resistant properties necessary for a quality traditional wooden hot tub.
Knots and wavy grain are also something to be completely avoided. Knots can be uncomfortable to sit on or lean against, and are also prone to leaking. Wavy grain can lead to unusually warping, cracking and eventual leaking.
|Equally important is the cut of the wood, or the direction
of the grain. Less than 25% of wood milled is "vertical grain", making it
considerable more expensive (up to twice the cost). However, vertical grain wood is
infinitely more desirable than the cheaper and more plentiful flat grain.
Unlike vertical grain, flat grain is prone to splintering, pealing, warping and showing signs of premature wear and tear. Vertical grain is much more durable, much more comfortable to sit on, and will last up to twice as long!
Others may claim to use clear, vertical grain wood, but looking at their pictures frequently shows something completely different.