Can a Deck Support a Hot Tub?
It depends…
Some decks can support the added weight of a hot tub, while some may require additional structural reinforcement.
Before you start shopping for the perfect hot tub to complement your deck, it's important to ensure that your deck can support the weight of a hot tub. Not all decks are equal, and not all can support a hot tub's added weight. The goal of this article is to help educate you about hot tubs being placed on decks and other methods of incorporating a hot tub with a deck.
Can you add a hot tub to an existing deck?
Many factors will impact whether or not your existing deck can support a hot tub. Some of these factors include, but are not limited to:
the age of the deck
type, size, and depth of foundation(s)
joist size, spacing, and material type
beam size and placement
general construction practices
All of these factors and more must be considered, and closely evaluated to determine whether your deck can support your new hot tub. Unfortunately, there is no quick and easy way to determine if your deck will support the hot tub that you want.
A structural engineer, or professional deck builder, such as Align Decking, will be able to assess your existing deck and determine whether it can support the additional load of a hot tub, water, and occupants.
Some existing decks may be able to support a fully loaded hot tub exactly as is, some may require additional foundations or structural members, while some may require extensive refurbishment. If you have an existing deck and are planning to add a new hot tub, please reach out to the experts at Align Decking!
How to determine the load exerted onto a deck by a hot tub
Determining the load exerted by a particular hot tub is an important first step in figuring out if a deck can support a hot tub. To calculate the exerted load of your hot tub, here’s what you’ll need:
Weight of the empty hot tub (dry weight) – You can typically find this information on the hot tub manufacturer's website.
Weight of water in the hot tub once filled – Water is heavy, with one litre weighing 2.2 lbs. This will need to be factored into the total weight.
Occupancy of the hot tub – The weight of the hot tub occupants also needs to be considered when determining the total load exerted. Everyone’s weight is different, but we can use an average of 180 lbs per person.
Footprint area of the hot tub – To determine the load of your hot tub, you’ll need to know how large of an area the weight is distributed over. This can be easily calculated by multiplying the length and width of your hot tub. For example, a 7ft. x 7ft. hot tub has a footprint area of 49 square feet.
Once you have all the above information, you can use the following calculation to determine the load exerted per square foot:
(Dry Weight + Water Weight + Weight of Occupants) / Footprint in Square Feet
Here’s how that might look in practice. I’ll use my hot tub as an example, which weighs 800lbs empty, holds 1840L of water, has 6 seats, and measures 10ft by 10ft.
(800lbs dry weight + 3680 lbs water weight + 1080 lbs occupant weight) / 100 square feet = 55.6 lbs per square foot
Here you can see that my hot tub exerts a load of 55.6 lbs per square foot. I’ll need to be sure that my deck can support at least 55.6 lbs over each square foot of decking. We recommend adding a 2x safety buffer to account for other dynamic loads, so my deck should be able to support 110 lbs over each square foot.
What to do if your deck can’t support your hot tub?
If your deck in its current state can’t support the weight of your fully-loaded hot tub, you generally have two options:
Option 1: Modify or ‘upgrade’ your existing deck
Option 2: Incorporate the hot tub with the deck in a different way
Upgrading your existing deck to support a hot tub
Many decks not currently capable of supporting a fully loaded hot tub can be modified to do so. Because every deck is different, the scope of the cost of upgrading your deck to support a hot tub can vary greatly. Sometimes, the addition of extra joists may be all you need. In other cases, extensive structural framing and foundation work may be required. In most cases, this upgrade process will require the removal of the decking surface. The cost of upgrading a deck to support a hot tub can range anywhere from $1000-$10,000.
For decks requiring extensive upgrades, it often makes more financial sense to start from scratch and use the opportunity to build a new deck.
Whatever the case may be, the experts at Align Decking can walk you through your options and help you make an informed decision.
Incorporating a hot tub with a deck in a different way
If your deck isn’t suited to supporting the weight of your hot tub, and you aren’t interested in rebuilding or upgrading, you still have options! Consider placing the hot tub on ground level, directly beside your deck. This often allows occupants to enter and exit the tub from the deck, without worrying about structural load limitations.
Can a Deck be Built to Support a Hot Tub? What should you know?
Yes! A new deck can absolutely be constructed to support the weight of a fully loaded hot tub. In fact, we do it all the time!
During the consultation and design phase, be sure to let us know if you plan on adding a hot tub to your new deck. It helps to have a model picked out already, as each hot tub will have a different weight.
The basic information we will need from you is:
What hot tub model do you want
How do you want it incorporated into the deck
On top of the deck or
Recessed into the deck
Once we have an idea of the hot tub you have in mind and how you want it installed, we can determine the maximum load it will exert and engineer your deck with this in mind. This process involves comparing the load that your hot tub will exert and referencing engineering tables laid out in the Ontario Building Code to determine the types of building materials required, joist spans, and other necessary construction requirements to meet the required load-bearing standards.
Types of Hot Tub Installations on Decks
There are two basic ways in which we can incorporate a hot tub with your deck. Hot tubs can be placed directly on top of your deck, or they can be recessed into the deck, creating an “in-ground” look. Our sales team will work with you to determine which method best fits your needs and budget.
When placing a hot tub on top of your deck, we engineer the footings and beams underneath the hot tub to accommodate the added load. Often, customers also request stairs be built with this method, providing an easy way to access the hot tub from the deck level. This installation method also keeps the access panels free and clear, making maintenance or repairs a breeze!
For recessed installations, the hot tub can often be placed on the ground, with the deck being built around the hot tub. With this installation method, access panels may need to be added to your deck for maintenance and repair purposes.
Both methods require special considerations and will add cost to a project, whether this be from added materials, increased labour hours, or both. Reach out to us so we can give you a free, accurate quote for your new hot tub deck project!
Other Important Things to Keep in Mind
Loads and structural requirements aren’t the only things to think about when considering integrating a hot tub with your deck. Here is a handy list of other things to consider before planning your dream hot tub deck:
Location and distance from the house: The desired final location of your new hot tub should be carefully considered before moving on to installation. If privacy is important to you, consider a location close to an existing wall, or incorporate a privacy screen into the design. The distance from the house is also an important thing to consider, especially in our cold Ontario climate! If the hot tub is too far from the house, you’ll be less inclined to use it. What may seem like a short distance feels a whole lot longer when it’s below 0 and you’re in a bathing suit!
Accessibility: Another important consideration is the accessibility of the hot tub. This includes ease of accessibility for users, and ease of access for maintenance, repair, and installation purposes.
Hidden costs: It’s essential to consider all the costs of a hot tub before deciding to integrate one into your deck. Some lesser-considered costs include delivery and installation charges, electrical panel installation or upgrades (most tubs require 240V), maintenance costs, and a water source to fill the tub.
Site access: Hot tub delivery services can get hot tubs into some seriously compact spaces, but even they have their limitations. If the delivery company can’t carry the hot tub into your backyard, expect the delivery cost to increase drastically. For some installations, using a crane and lifting the hot tub over the house may be the only option.
Wrap Up
In conclusion, adding a hot tub to your deck can be a great way to relax and unwind, but it's important to make sure that your deck can support the weight of a hot tub. Factors such as the age of the deck, type of foundation, joist size and spacing, beam placement and general construction practices must be considered and evaluated before deciding to add a hot tub to an existing deck. To determine if your deck can support a hot tub, it's best to consult a structural engineer or professional deck builder. If your deck can't support a hot tub, there are options available such as upgrading your existing deck or incorporating the hot tub in a different way. We recommend reaching out to the experts at Align Decking to help you determine if your deck can support a hot tub and help you plan the best solution for your needs.