An aging deck may not be the best candidate for a hot tub. Exposure to the elements and ultraviolet rays can weaken deck boards over time. Also, older decks may not be built to today's code ...

In-ground hot tubs: Often referred to as "spas," in-ground hot tubs are custom-built into the ground ... to decide on a location (a patio, porch or deck are popular picks) and measure it.