Your deck is a place where you host your family and friends to relax, entertain, or enjoy a meal surrounded by nature.
Maybe you want to take it to the next level and add a hot tub to your deck, but can your deck support a hot tub? What about if your deck is elevated?
Installing a hot tub on your deck can help maximize your investment, and the closer the hot tub is to your house, the more useful it’ll typically get. You can relax after a long day or have friends over to catch up all within walking distance of your home.
Can You Put A Hot Tub On A Deck
Yes, you can put a hot tub on your deck if it meets certain specifications and has enough support to ensure the hot tub doesn’t breakthrough.
Decks on the ground level to two feet up can easily support around 100 pounds for every square foot, but any decks that get above two feet off the ground will need additional supports put in.
The support posts can be a maximum of 30-inches apart and should be anchored in poured concrete to ensure they don’t move.
There is a lot more you have to know about decks and hot tubs before you take on this project because when they’re full of people and water, it easily pushes your hot tub’s weight over 5,000 pounds.
We’ll go over how you calculate how much weight your deck can safely support, how to safely put a hot tub on your existing deck, and where to add additional supports to make the area safe below.
The Average Hot Tub Weight
There are different kinds of hot tubs available, and each hot tub will have a different weight when you talk about standalone structures.
There are smaller two-person units, medium four or five-person hot tubs, large six to eight-person hot tubs, and inflatable options. On average, your hot tub weighs a minimum of 500 pounds when it’s empty.
It’s always in your best interest to double-check with your hot tub manufacturer about your model. Below is a rough estimate on how much your hot tub will weigh when it’s empty, full of water, and full of water with occupants. They include:
- Two or Three Person Hot Tubs – 600 pounds empty, 2,575 pounds with water, and 3,000 pounds with people and water.
- Four or Five Person Hot Tubs – 750 pounds empty, 3,700 pounds with water, and 4,420 pounds with people and water.
- Six to Eight Person Hot Tubs – 800 pounds empty, 4,300 pounds with water, and 5,500 pounds with people and water.
- Two or Three Person Inflatable Hot Tubs – 2,200 pounds with water and 2,700 pounds with people and water.
- Four to Six Person Inflatable Hot Tubs – 2,700 pounds with water and 3,700 pounds with people and water.
How Much Weight a Deck Can Support
Generally speaking, the higher your deck is from the ground, the less weight it’ll be able to support for every square foot. In the following example, we’re going to assume you have a larger six to eight-person hot tub:
Get the weight of the empty hot tub
- 800 pounds
Find the number of gallons of water the hot tub holds and multiply it by how much a gallon weighs
- 525 gallons x 8.34 pounds = 4,278.50
Add your results from step and two
- 800 pounds + 4,378.50 pounds = 5,178.50
Multiply the maximum number of people the hot tub holds by the average user weight of 175
- 8 people x 175 pounds = 1,400 pounds
Add your total to the previous total
- 5,178.60 pounds + 1,400 pounds = 6,578.80
Divide your total by the hot tub’s total number of square feet
- 6,578.80 pounds / 64 square feet = 102.79
So, according to your calculations, you can see that the biggest hot tub is over 100 pounds for every square foot if you have eight people in it at once.
This makes it impossible for your deck to support if it’s over two feet off the ground without additional support posts.
Figuring Out of Your Deck Can Support a Hot Tub
Despite the fact that most hot tubs are relatively small, they can bring a lot of weight that gets concentrated in a very small area.
So, a deck that is more than two feet off the ground and that has support posts every six feet won’t be strong enough to hold your hot tub up when it’s full. However, there is good news.
If your deck is higher off the ground and easy to get under, it’s relatively easy and straightforward to add more support posts and beams to help distribute the weight more evenly to keep your deck stable.
If your deck is two feet or less above the ground, you most likely won’t need to add additional support posts or beams, but it’s a good idea to get in touch with a professional contractor before you proceed to see what they recommend to keep your deck stable.
This being said, if you have a deck that is just off the ground, it can support right around 100 pounds for every square foot. This is enough support for most medium-sized hot tubs that have both water and people in them.
Additional Factors to Consider
Since you could end up with a catastrophic failure of your deck if you don’t do your calculations correctly, you want to be 100% sure in your decision to add a hot tub to your deck. Other factors will come into play, and we’re going to highlight the most important ones below.
If you plan to install a hot tub and already have a deck up, you want to consider how old it is. The wood on an older deck could be warped or weathered and need to be replaced because they’re weaker.
The construction standards may not be up to par with today’s guidelines either if it’s an older structure, and everything from the main beam locations to the joist hangers and lag screws can impact how structurally sound your deck is.
It’s hard to imagine what sounds better than walking out your doorway onto your deck from your bedroom and getting into a hot tub. But, if the hot tub completely takes over space because you have a smaller deck, this can lead to it feeling too cramped to enjoy.
Make sure you’re willing to lose space for your hot tub where you could potentially put a table, couch, or other outdoor furniture.
A contractor could be happy to give you a plan to help you reinforce your deck to support the weight of your hot tub, but many people are surprised by just how much they have to pay to reinforce an existing deck.
Prices could start as low as $500 for minimal work, and they can easily go up to $5,000 or more, depending on how many support posts you need and how you want them anchored into the ground.
Now you know that you can put a hot tub on your deck as long as you’re mindful of the weight and whether or not your deck can safely support it.
You can calculate the weight and decide if you need to reinforce the deck before you add your hot tub and plan out your project to allow you to create an oasis right outside of your door.