Building a Spa and Hot Tub Deck

Some homeowners don’t want a hot tub obstructing their view and opt to have it seated flush with the deck. This can make it harder for older people to get in and out without some assistance or a railing.

One of the most popular deck features for most homeowners is a hot tub or jacuzzi. However, what most homeowners don’t realize is that you can’t just buy a hot tub and put it on your deck. Because of the weight of the water and the unit, electrical issues, and building plan permits your deck must be engineered for the hot tub.

That means if you’re planning to build a deck you need to plan it around your hot tub – including the weight, dimensions, electrical demand, water (hose) and electrical access to the tub.

Most experts say the number one rule when deciding where to place the hot tub is to put it as close to the patio or entryway as possible. Not only does this encourage the use of the hot tub in colder weather, but there’s also less snow to shovel before you can access it. Because the special electrical wiring needed to hook up the hot tub is expensive, the shorter the run of the power cord, the less expensive it will be.

Hot tubs must be periodically drained and cleaned as well. Having a way to drain them easily is important too.

This Japanese hot tub has ample clearance for guests, and at a bench height, it’s easy for guests to get in and out of the hot tub safely.

One of the most popular deck features for most homeowners is a hot tub or jacuzzi. However, what most homeowners don’t realize is that you can’t just buy a hot tub and put it on your deck. Because of the weight of the water and the unit, electrical issues, and building plan permits your deck must be engineered for the hot tub.

That means if you’re planning to build a deck you need to plan it around your hot tub – including the weight, dimensions, electrical demand, water (hose) and electrical access to the tub.

Most experts say the number one rule when deciding where to place the hot tub is to put it as close to the patio or entryway as possible. Not only does this encourage the use of the hot tub in colder weather, but there’s also less snow to shovel before you can access it. Because the special electrical wiring needed to hook up the hot tub is expensive, the shorter the run of the power cord, the less expensive it will be.

Hot tubs must be periodically drained and cleaned as well. Having a way to drain them easily is important too.

Should Your Hot Tub Be Level or Elevated?

Depending on how young or agile, or older and less physically stable you are, the level of your hot tub will make a huge difference. You want you, your family and guests to be able to get in and out of the hot tub without falling, or feeling unsteady or safe. If you do choose to elevate the hot tub, or must elevate it in order to be able to service it from underneath later, 20-inches from the deck to the base of the hot tub is ideal. If you do elevate your hot tub, have either safety railings or a bench or other design feature to help small children and the elderly get in and out securely.

Homeowners decide on all kinds of configurations – from bench height so they can sit on the edge of the tub and swing their legs into the water, to flush with their deck. All kinds of configurations are possible but experiment with tubs in the manufacturer’s showroom to see what height might work best for you. Thinking about the best height isn’t nearly as effective and realistic as actually testing different heights.

Clearance

At some point, your hot tub is going to require servicing, maintenance or repair. That means you, or the service person will need to be able to access it from all sides. You’ll need a minimum of 18-inches from panel to wall or railing, and preferably two feet to allow the technician to work. Since most hot tubs have a 15-year life expectancy you can expect to encounter leaks and other issues sometime within that time period. That means your technician will need to be able to access the entire hot tub without having to be a contortionist to do so.

Clearance isn’t just a service requirement. You and your guests shouldn’t have to squeeze past the hot tup to gain entry. Leave enough room for people to easily access and get out of the hot tub safely. Having a bench, towel hooks and an area where people can remove their shoes or store their personal effects is nice, as is having either a platform or place to set a drink or a bottle of water.

Notice this hot tub is resting on a concrete slab with ample clearance all around. Water can drain easily from the side into the ground. It’s at a height that’s easy for any child or adult to get in and out of safely.

Load Calculations

A US liquid gallon of water weighs about 8.34 pounds. The average hot tub holds about 400 gallons, or 3,336 pounds, plus the weight of the tub. Add one to three adults weighing another 500 pounds or so and you can see why you need to make sure your deck is engineered to hold the extra weight and stress of a hot tub. All hot tubs must be placed on a flat, level surface, such as a concrete slab or a deck, without any shims.

Other than that, many structural and design decisions depend on the particular hot tub chosen. Picking your hot tub before you decide on a deck build is important to ensure your deck and tub are compatible and safe.  Once you and your contractor know the tub’s dimensions, dry weight, water capacity, and suggested occupancy they can figure out the weight that the slab or framing will need to support. You’ll need a deck design that can support at least 101 pounds per square foot. Many homeowners use a multi-level deck – with stairs leading down to a ground level slab where their hot tub is. But, you can have a hot tub at any level if the deck is engineered for it. It’s better to overbuild than underbuilt. If you’re not ready for a hot tub yet but plan to get one in the future, make allowances during the build rather than try to re-engineer the deck later. It’s more expensive to retrofit a deck than build it for an anticipated future use.

What You Need to Know About Spa and Hot Tub Decks

While a licensed contractor should know about permits, heights, and engineering for building a deck with a hot tub, it doesn’t hurt to educate yourself about what is needed.

Know the code. By code, the emergency shut-off switch needs to be in sight of and between 5 and 15 feet from the tub or spa. If the tub will be supported by a concrete slab, the wiring will need to be run in conduit, which should be placed before pouring the concrete. Keep in mind that hot tubs can’t be placed directly under or within 12 feet of overhead power or telephone cables, so take a close look at where your power lines enter your home. It’s not a code requirement, but if you place your hot tub under trees expect to do extra cleaning come fall and winter.

As if the weight of the hot tub weren’t enough, here in Colorado snow loads are also a concern. Snow is simply frozen water and 3-to-5 feet of snow on top of your hot tub can become an issue.

Some hot tubs can be plugged into a GFCI-protected 110v/20-amp outlet, but most require a 220v/50-amp electrical connection to heat the water and simultaneously run the jets. A licensed electrical contractor will be needed to obtain the electrical permit, tie into the existing power, run the wiring in conduit, provide the emergency quick-disconnection box, and do the hook-up to the power panel inside the tub’s control box.

If all that sounds intimidating, we understand. That’s why we have the best contractors in the state to ensure your deck goes up safely and remains safe throughout its lifetime. If you’d like to know more about designing a deck for a spa, jacuzzi or hot tub, contact us for a free consultation.