The weight of a hot tub depends on the manufacturer and size, but a typical 7.5-foot square unit weighs 855 pounds when it is empty. However, the filled tub contains 450 gallons of water and has room for up to seven people, increasing the weight to 5,665 pounds.
If a homeowner is considering installing a hot tub on a deck, it is essential to provide enough support to prevent the collapse of the structure. The area the tub occupies is approximately 56 square feet, so the contractor should construct the deck to support a minimum of 101 pounds per square foot. In many municipalities, building codes require the approval of an engineer before placing the unit on an elevated deck.