Hot Tub Deck
Hot tub or spa decks should always be "overbuilt". The average 8' x 8' hot tub weighs over 5,000 lbs when filled with water and people. Never place a hot tub on an existing deck that wasn't designed to support the massive loads. A new platform with large footings at least 22" in diameter should be installed below each corner of the tub to evenly distribute the weight. Use substantial framing materials such as 2x10 or 2x12 joists installed 12" on center with nailed double beams. Use 6x6 support posts with bracing if necessary. Also make certain that all your fasteners and hardware are correctly installed and are compatible with the treated substructure.
If your deck will be built low to the ground you may want to consider setting the hot tub on top of a poured concrete slab beside the deck. . For high decks some builders also recess the hot tub platform. This makes entering and exiting the hot tub easier. Always plan ahead to leave room access to the control panel.
Privacy can be an issue with hot tub decks. Many people choose to install privacy screens along with overhead pergolas to enclose the space. You may also want to install some built in benches or shelves to place towels and drinks. Lighting can also be a key feature to allow you to enjoy your hot tub after dark.