Decks and hot tub build considerations & design ideas

decks and hot tubs

Decks and hot tub build considerations & design ideas


There are few things that can enhance your deck and your experience of it like a hot tub. As decks become more frequent additions to homes and properties, more homeowners are beginning to add onto their decks with built in benches, gazebos, pergolas, and equipment like hot tubs. All of these additions can help you enjoy your deck more, and get more use out of it.

However, adding something like a hot tub to your deck requires a lot more thought than simply purchasing one and setting it down. Hot tubs are heavy. They require support, as well as electrical and water supply, and they need to be positioned just right for maintenance, safety, and ideal using conditions. So, before you set out to build a new deck or add a hot tub to an existing structure, be sure to take these factors into consideration.

Choosing Your Tub

Hot tubs, jetted tubs, and spas comes in a wide range of different sizes, shapes, and configurations. They also come in several different weights, with different electrical needs, and different maintenance and cover options.

Ideally, you want a tub that will be large enough to accommodate at least four people. You’ll also want to plan your tub’s location so that it will give you enough room to maneuver about it, store the cover when it’s in use, and to reach the interior for necessary and regular maintenance. If you are adding a hot tub to an existing deck, you’ll need to size your tub to the area you are placing it in.

The weight of your tub will also affect your deck and where you’ll be placing it. Most decks are not built to handle the weight of a tub filled with water and people. The average hot tub will weigh around 800 to 900 pounds, and will take on an additional 3,000 to 3,500 pounds of water. Each user adds another 100 to 200 pounds, making your deck need to handle up to 150 per square foot in the area the tub will be installed.

For this reason, you’ll want to select your tub first, then consult a structural engineer on how best to add supports to your deck to accommodate it. No matter what material you build your deck from, it will need to be designed to hold this extra weight in the location you place the tub.

Determining the Area

Whether you’re placing a tub on an existing deck, or you’re building to suit, you’ll need to put some thought into the tub’s final location. Your tub needs enough room on all four sides for air to circulate, for people to pass, for maintenance workers to access the machinery, and for the cover to sit when it’s in use.

In addition, you may also want to consider the location from other standpoints as well, including:

  • Privacy: How visible will the tub be from the yard, the house, or your neighbor’s yard
  • View: If you have a garden or a scenic view outside your deck, consider placing the tub to give you the best view when it’s in use
  • Other functions: What other functions will your deck have? You may not want your tub placed right next to a grill or eating area, but built in storage or seating may be a good idea if you entertain a lot
  • Utilities: Your tub will need to be wired to the electrical supply of your home, and you’ll need to be able to reach it easily with a hose to keep it filled as well.
  • Sun and Shade: Will you use your hot tub primarily in the day or night? Will trees cover it or do you want a sunny location? Pay attention to the path the sun and shade take over your yard during the day to find the spot that best suits your needs.


In addition to the tub itself, put some thought into the type of decking that you use as well. Remember that hot tubs often include a few things that can affect both your decking and your use of the area, namely water and moisture constantly hitting and splashing the deck, and the fact that you’re often barefoot when using it.

Using pressure treated wood on your deck with a hot tub means two things for most homeowners. First, you will constantly be scraping, staining, and waterproofing your deck in an effort to protect it from moisture and the damage that it can cause. This can add up to a lot of maintenance, especially since moisture can lead to issues such as mold, mildew, and wood rot, all of which can be expensive and time consuming to combat.

Second, pressure treated wood will eventually begin to splinter, particularly after exposure to moisture. So, running barefoot from the tub to the house can become an uncomfortable experience for many users over time.

Composite decking has issues that can become drawbacks when used with a deck as well. The material can get very hot underfoot, making it tough on bare feet in the summer. And while the surface of the decking is plastic and impervious to moisture, the interior of the planks is not. So, any crack or surface penetration in the planks may lead to swelling or warping of the deck over time as splashes and spills from the tub occur.

For homeowners looking for a moisture resistant, non-splintering decking material that will perform well with a hot tub year after year, there is modified wood. Modified wood is sustainable softwood that has been treated with a bio-liquid and heat to render it harder and more durable than most hardwoods. The wood is moisture and insect resistant and doesn’t splinter like pressure treated wood. So, it can be safely used with a hot tub without the added maintenance. And because it’s made of real wood, it can give you the style, character, and personality you want for your deck as well.

Creating a Safe Tub

Hot tubs combine two things that are not generally meant to go together – electricity and water. Therefore, part of the planning you’ll need to include in your deck design is how to create a safe tub area, as well as an enjoyable one.

Whenever electricity is installed near water, a GFCI outlet is necessary; it will shut the power supply to the tub down if it senses any fluctuations in the current, helping to prevent electrocutions and fires. If your tub is larger than one meant for four people, you will need to upgrade your electricity to handle a 220-volt, 50-amp connection, protected by a GFCI. Smaller tubs can likely be installed on a standard 120-volt, 20-amp connection.

Keep in mind that your tub will need to be installed on a concrete pad, not directly on top of your decking. Therefore, the wires for the tub will need to be laid beneath the concrete pad, before the tub itself can be installed. This will help conceal the wiring, and create the safest, most efficient installation for your tub and deck.

You’ll also need to plan for an emergency shut off switch for the tub. Per building codes, this will need to be located 5 to 15 feet away from the tub itself. Consider placing this in the path most people will take to enter and exit the tub, so it’s easily located, even by guests, in the event of an emergency. You’ll also want to consider this path to and from the closest doors in general when planning on safety to ensure that the path is direct, well lit, and easily navigated no matter how far from the door you end up locating the tub itself.

Deck Designs

Adding a hot tub to your deck is a great way to increase its value and your enjoyment in the space. There are many different deck designs that can help accommodate a tub, as well as further increase the value and function of the area at the same time. Check out these designs for some style ideas.

Plexiglass Tub

Architect: hacedor/maker: arquitectos 

Not all hot tubs need to be surrounded by wood, casing, or padding. This plexiglass tub was built right into the corner of a deck, with access allowed both from above, by simply sitting and slipping in, and from the lower level thanks to a set of well-placed stairs. Strategically placed vents surrounding the tub help keep the decking dry, while the clean lines of the plexiglass the smooth wood planks complement one another, creating a contemporary hot tub deck design.

Built-in Hot Tub

Architect: Homexo Photo by: Studio Oslo

If you’re building your deck with the intent to install a hot tub on it, consider building the tub right into the deck, like this rooftop design. The tub surround was created out of the same decking material that covers the rooftop, giving a clean, elegant look to the entire space at once. By using the same decking, it helps create an optical illusion that the tub and the deck are both larger than they are, and helps the tub to blend in with its surroundings when it isn’t in use and the lid is firmly in place.

Sunken Tub

Architect: Vettermann + Rickens Photo by: Salih Usta

In most cases, you’ll want to place your hot tub on the deck, rather than in it, particularly if you have children who may fall in. However, in some installations, sinking the tub into the deck can create a very clean and contemporary appearance for your deck and your landscaping. Sinking the tub helps to create a more minimalistic appearance for the area, and makes sure that the tub isn’t the focus of the design as a whole. Instead, the tub’s focus becomes more functional, rather than aesthetic, which can fit in well with some types of designs.

Create the Deck of Your Dreams

Many people today are adding on more to their decks than ever before. Barbeques, fire pits, and hot tubs are all showing up on more decks and terraces as homeowners strive to get more enjoyment and function out of this outdoor living area. Keep in mind that placing a hot tub on a deck is more complicated than simply choosing one and setting it down. Make sure that you take structural, placement, and safety issues into consideration when planning for your new hot tub, and that you invest in a decking material like modified wood by Kebony that will hold up well to the years of use that your hot tub and deck are going to get. Pay attention to these and other details of the design, and build a deck that you’ll be sure to use for the next several years to come.