Can You Put a Hot Tub on a Deck?

If you’re thinking of getting a hot tub, your deck can seem like the perfect place to put it. The good news is, you can put one on a deck. But you’ll need thoughtful planning and the help of a contractor or structural engineer to do it safely.

If this project is on your wish list, read on for expert tips from four industry pros: Dusty Walters, owner of a hot tub sales and service company; Chris Hoppe, a structural engineer; Chris Jacobs, a licensed contractor; and Dennis Moore, a hot tub installer.

How To Tell If Your Hot Tub Is Deck Friendly

When purchasing a hot tub for your deck, carefully consider its weight and size.

Weight

Hot tubs are heavy. Even when empty, they can weigh 400 to 1,000 pounds. Filled with water and people, that number can soar to more than 10,000 pounds for larger models. “A hot tub full of water can weigh as much as a car,” Hoppe says. Most decks can’t support a load that large.

However, most decks can handle smaller to medium-sized tubs that hold three to six people and less than 600 gallons of water. These usually weigh 4,000 to 6,000 pounds when occupied a more manageable number. “A lot of tubs can fit on a residential deck, unless it’s a monster,” Jacobs says.

Size

Hot tubs have standard size ranges for small, medium and large models.

To determine what size hot tub will fit on your deck, use painter’s tape to mark these dimensions on the deck floor. See which size leaves enough room for walking, furniture and maintenance access. You’ll need 24 to 36 inches of clearance around all four sides.

Deck Considerations for a Hot Tub

Strength

“Decks must be properly supported and built to support the weight of a spa,” Moore says.

Most decks are built with 2- by 8-inch joists (floor supports) spaced 16 inches apart from the center of one board to the center of the next. Decks built this way can support 50 pounds per square foot (pps).

“What this means is, if you take a 12- by 12-inch bag of sand that weighs fifty pounds and laid it on every square foot on the deck, that is what it can hold,” Jacobs says. Put another way: A 100-sq.-ft. deck built to code could hold 5,000 pounds.

So how much weight can your deck handle? Whatever your structural engineer or contractor says it can. “We always recommend having an engineer check the deck to make sure it can handle the weight of the spa,” Walters says.

In the early planning stages, you can do some measuring and basic math to get a rough estimate. Go underneath the deck and measure the width of your joists and their distance apart. If they’re eight inches wide and spaced 16 inches apart, multiply your deck’s square footage by 50 for a rough idea of how much weight it can hold.

If your deck’s joists are a different measurement, consult with a pro to determine its weight limits.

Height

If your deck is really high off the ground, installation is still possible, but it will be more complex and expensive.

Walters doesn’t recommend carrying hot tubs on stairs, because it can damage the deck or spa. Instead, he uses a crane for installations higher than four or five feet off the ground. Make sure to factor in this cost to your project total.

Proximity to utilities

You’ll need a properly rated receptacle installed near your hot tub. The longer the distance between the hot tub and the main breaker box, the more expensive this will be. So consider this cost when determining if your deck is the best location.

Access to water will be necessary as well. A hose should reach the hot tub for filling and occasional topping off. Check the proximity of an outside spigot to your deck, or hire a plumber to add one closer to the tub.

Age

An aging deck may not be the best candidate for a hot tub. Exposure to the elements and ultraviolet rays can weaken deck boards over time. Also, older decks may not be built to today’s code requirements and could pose a safety risk.

If your deck is showing signs of decay weathered or split boards, rotting posts or loose railings consult with a contractor to assess its safety.

Reinforce the Deck

If your deck can’t hold the weight of the hot tub you want, structural reinforcements can be installed to increase its strength. Your engineer or contractor may suggest adding wider joists more closely spaced to support the additional weight.

They also may want to add or widen the deck’s footings. Footings are the structural support posts of a deck that evenly transfer the load to the ground. “Without stronger footings, [the deck] could start to sink under its own weight,” Jacobs says.

Sink the Hot Tub Into the Deck Instead

Another option is installing a recessed hot tub. Instead of resting on top of the deck, the tub sits on a poured concrete slab under it, so the top edge is flush or just above the deck floor. This eliminates the need to climb over the walls to enter and exit.

This setup has deck height requirements and must allow for maintenance access as well. “There are very specific things that need to be done to create service access on all four sides of the spa if you sink the spa into the deck,” Moore says. This can include decking and lattice skirting which can be removed to allow service workers to complete maintenance tasks.

About the Experts

Dusty Walters owns Colorado Springs Hot Tub Sales and Service in Colorado Springs, Colorado. He has 20 years of industry experience.

Chris Hoppe is a structural engineer in Philmont, New York with degrees in civil engineering and architecture from State University of New York at Buffalo. He has more than 30 years experience.

Chris Jacobs runs Barron and Jacobs, a remodeling construction company in Leeds, Massachusetts. He is a licensed construction supervisor with 36 years of construction experience.

Dennis Moore has been a delivery administration team member at New England Spas in Auburn, Massachusetts since 2020.

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