A spa or hot tub on your deck adds a remarkable visual emphasis to your home. It involves more than just purchasing a spa and placing it on the deck. An average 8×8 spa fully loaded with people and water can easily weigh 2 ½ tons. Most decks aren’t designed to hold that much weight. This is the equivalent of placing a car, or mid sized SUV on your deck. There are two things that can be done if you’re still dying to add a spa to your deck. The existing decking can be reinforced or an additional platform can be installed on the ground. The deck can then be built around the spa.
Now, before you start any decking project check with local building codes and regulations. There are many different variables one can encounter when installing a deck that is made to support a spa or hot tub. Follow all manufacturer’s installation instructions for the individual products used on the project. Make sure you contact a licensed contractor that is familiar with spa installation on or around decks, and because this is a special project that involves electricity and plumbing, contact a licensed electrician and plumber prior to installation.
Hot Tub Framing on a Deck
As previously mentioned an average 8×8 hot tub weighs around 5000 pounds fully loaded with water and people. There are ways to reinforce your deck without having to demolish it and start from scratch.
- First, add additional fasteners to the ledger board to add extra security from the deck to the house.
- Remove any blocks underneath the deck.
- Extra joists are going to be a significant part of the reinforcement of the structure. Add the new joists to the existing joists and hold them tightly together with a clamp. Secure them with 2 1/2” stainless steel deck screws. Add these screws every two feet.
- Fasten extra joist hangers on the house side of the deck.
- Replace the blocks. The new blocks will need to be a little bit smaller, considering the space between each joist has been shortened by adding the new joists.
- Add extra beams at each corner of the hot tub underneath the deck for added support.
Hot Tub Framing Within a Deck
You haven’t built your deck yet, or you still aren’t convinced that adding joists and fasteners will be secure enough. Don’t worry, there is still another way to enjoy a hot tub on your gorgeous deck. The hot tub is placed on the ground and the deck is built around it.
- Install a concrete slab for the hot tub platform. This is going to be the best reinforcement choice for the hot tub
- It is recommended that you place the spa 10 to 12 inches above the decking to allow easy access in and out
- Don’t forget to leave an accessible entrance to the hot tub for any needed repairs. Poor installation and lack of entry will cause you issues if the hot tub needs repaired.
No matter which installation you choose, your deck is going to look gorgeous. Just make sure you take the necessary steps to reinforce the surroundings of the spa. Have fun and enjoy your outdoor space. Don’t forget to contact a licensed contractor that is familiar with these types of installations and check the local building codes and regulations.
I’m planning to install a hot tub on an elevated deck that is approximately 10 feet high. Is it a good idea to to put down pressure treated plywood on the deck where the hot tub will be located first before putting the hot tub on the deck?
Thanks for your input,
No this is not recommended because it would trap and hold water. As long as your deck is properly framed for the hot tub you could place the hot tub on the joist (again if it’s properly framed and supported). Hot tubs weigh a lot when they are filled with water and people so make sure you check that your deck is properly supporting the hot tub for your size hot tub.