There aren’t many better ways to end a Utah winter day than in a hot tub with snow on the ground and the mountains glowing at sunset. A deck built around the tub makes it feel like part of the house instead of a box sitting in the yard. Composite and PVC decking are a great match for a hot tub, but the structure underneath needs careful planning. Here’s what we think about when we build one.
A hot tub is a heavy, concentrated load
A filled hot tub with people in it is one of the heaviest things you can put on or near a deck. The water alone weighs far more than a crowd of people spread across the same area, and all of that weight sits on a small footprint.
A standard deck is not designed for that. Setting a hot tub on an existing deck without checking the structure is one of the most common ways decks get overloaded. The weight has to be carried by framing and footings designed for it.
Three ways to support the tub
1. On its own pad, with the deck built around it. This is often the simplest and strongest option. The tub sits on a concrete pad or other engineered base at ground level, and the deck is framed around it. The deck can be built up to the height of the tub’s lip, so the tub looks recessed, or partway up, so it’s easy to sit on the edge and swing your legs in. The deck itself never carries the tub’s weight.
2. On the deck, with framing engineered for it. If the tub has to sit on the deck surface, such as on a raised deck with no ground access, the framing under it needs to be designed for the load. That usually means closer joist spacing, larger beams and additional footings directly under the tub. On some projects that requires engineering, and your city’s building department will review it.
3. On a lower level. A two-level deck can put the tub on a low platform with its own support and keep the main deck free for seating and dining.
We decide which approach fits based on your yard, the deck height and the tub you’re buying. Have the tub’s specifications on hand, including its filled weight and dimensions, when you call.
Why composite and PVC work well
Hot tubs splash. Wet feet go back and forth all year, and in a Utah winter, that water freezes on the deck. Wood around a tub is constantly wet and needs frequent sealing. Capped composite and especially PVC decking absorb very little water, resist mold and staining, and don’t splinter under bare feet.
A few choices make a hot tub deck better:
- Textured boards for traction when they’re wet.
- A lighter color if the deck is in direct sun, so it stays comfortable barefoot.
- G-Tape or steel framing under a deck that will see constant water, to keep the frame from rotting.
Check the manufacturer’s care guide for any chemicals used around the tub, since spilled hot tub chemicals can affect some finishes.
Plan for access and service
Hot tubs need maintenance. The equipment panel has to stay reachable, and the cover needs space to open or a place to sit when it’s off. Plan the deck so you’re not building a wall in front of the panel. Electrical requirements for hot tubs are strict, and the power and disconnect locations should be planned before framing.
Privacy and wind
A hot tub in a Utah subdivision is often in full view of the neighbors, and an evening breeze off the mountains can cool things off fast. Privacy screens solve both.
On the Highland project, two hot tubs sit on a TimberTech Vintage English Walnut deck under a rough-sawn timber-frame pavilion, with black TimberTech HideAway privacy screens along the sides. The Sundance cabin deck holds a barrel sauna and a hot tub, with HideAway screens and a built-in waterfall bench.
A pergola or covered roof adds shade in summer and keeps snow off the cover in winter. See pergolas and covered patios.
Lighting for safety
Getting in and out of a hot tub at night, on wet steps, is where people slip. Low-voltage stair riser and recessed deck lights around the tub make the path clear. The Highland deck has recessed lights along every step, and the Sundance deck has lights set into the bench.
Under a second-story deck
Another popular setup is a hot tub on a patio under a second-story deck, like the Pleasant Grove Trex deck. The deck above becomes the roof. Adding Trex RainEscape drainage keeps water from dripping through the boards onto the tub area.
Plan it with the deck
The best hot tub decks are designed together with the tub from the start. We’ll show the layout in a 3D rendering once the job is booked and back the build with our 7-year workmanship warranty.
See more deck add-on ideas and our composite deck options, or contact us for a free estimate over the phone.