Top 12 Indoor Hot Tub Tips

Top 12 Indoor Hot Tub Installation Tips

So you want to install your hot tub indoors?

Most portable hot tubs are installed in the great outdoors.

This is just easier to do and manage, but indoor installations are also possible and popular in Europe and North America as well.

In the deep of winter, sometimes it is nice to just soak indoors, so for those who want to install a hot tub inside the home in a sunroom, basement, bathroom or other area, these top 12 tips should help provide the necessary considerations before taking the indoor plunge.

1. Choose a Hot Tub Model suitable for indoors.

Typically, a spa with less water volume will do better indoors.

These are the smaller and mid-sized hot tubs that are manageable.

Sometimes there is a restriction on what will actually go through doors, down stairs, around interior corners etc..

The 120 volt hot tubs that are plug and play are easier to install indoors.

Sometimes larger spas are able to be installed indoors when planned for during the construction phase or during an add-on or major renovation. Make sure it will fit and be able to be delivered.

2. Plan for water overflow.
If someone sloshes out hot tub water, or even gets the floor wet while getting in and out, the flooring around the hot tub should be able to accommodate water spillage or overflow. Not only should the floor tolerate water, but should also be slip-resistant when wet. Certain types of non-slip tile work best here. Having a floor drain installed is comforting as well.

3. Think about how the spa will be filled
Outdoors, the spa is just filled with a garden hose, but indoors sometimes plumbing fixtures are added to a nearby wall to make filling the spa easy. The water line can also be hooked up to or near the hose bib so that it can be filled from underneath the spa skirt. There are many ways to get water into the spa, but this should be considered as part of the indoor hot tub installation planning.

4. Wall materials and surrounding wall construction

If the spa is uncovered, it will steam the room up similar to a bathroom, so using green sheetrock or wall board similar to what would be used in a bathroom is the best course of action.

Cement walls, glass enclosures or other water-resistant drywall made for bathrooms and kitchens should be used.

A vapor barrier should be installed under the wall covering to prevent dry rot of studs, underlying wood members and joists.

5. Ventilation Fan
Just like a bathroom, the room that contains the hot tub will get high levels of humidity so will need a ventilation fan.

It should be a quiet one so it is not too disturbing. This vent fan is used to remove humidity from the room to avoid dry rot.

That noisy bathroom fan is not good enough for this application. A more robust, quiet and rust proof fan should be source for this task.

They can be ceiling, external wall or window mount fans.

Advanced fans include a timer, thermostat and humidistat in one unit. A HVAC contractor can help with this ventilation task and sourcing.

6. Temperature and Humidity Control
The indoor space should have its own temperature control to avoid condensation. An HVAC professional should be consulted. EPA recommends indoor humidity levels to not exceed 60%.

Keeping the hot tub covered when not in use will help minimize the evaporation of water. A Dehumidifier is a requirement and it should be able to remove excess moisture to stay within the acceptable range. 

7. Indoor Pool and Spa Odor
Use an ozonator or UV system and mineral sticks to reduce the amount of actual chlorine or bromine sanitizer needed to keep the water clean. Anything to reduce potential chloramines, bromamines or other chemical fumes. Use a proper HVAC system along with dehumidifier and exhaust fan. The HVAC contractor can determine the right amount of "air changes per hour" to assure clean, breathable air.

8. Weight Support of the Spa
The foundation or support structure under the spa should support the weight of the spa. This means it must support not only the weight of the empty spa, but also the weight of the water when full and also the weight of potential occupants.

This can quickly add up to thousands of pounds that need to be supported.  Most homes can handle anywhere between 100-300 pounds per square foot of weight depending on the construction standards, but the individual area where the spa is to be located needs to be properly supported. Of course a basement spa with a concrete slab underneath should not have any problem. The spa should also be evenly supported and be on a flat surface, not supported only on the edges.

9. Convenient Access
How will bathers enter and exit the spa and what path will need to be taken to get to the bathroom or changing area. That path should be short, slip resistant and thought out to avoid trapsing wet feet through more delicate flooring in the home.  

10. Interior Noise

Will the spa pumps disturb neighboring sleeping areas of the home. Most well-designed spas can be set to circulate a given times, so they don't circulate at night in the case the spa is located where it could be heard from those trying to get some shut-eye. Pumps can be mounted on vibration mats to reduce this noise. (There is also a little known trick that Hot Tub Outpost will share with those who want to install the spa indoors and are having pump noise issues - but that is only for Hot Tub Outpost clients).

In some instances, the installer may want to take the equipment pack and pumps out of the spa and route them elsewhere such as in a concrete bunker, but that opens up a lot of problems and is not recommended. Pump head is related to the water pressure available at the jets and the proper priming of the pump.

The ventilation around the pump is given in a typical hot tub cabinet and many times the warmth generated by the pump is used to heat the actual spa water, whereas in an external installation, this heat would have to be vented off. So taking the equipment out of the spa, besides being problematic from an operational standpoint, also is less energy efficient.

Nevertheless, these types of installations have also been successfully done, but there is just that much more to consider if equipment is to be relocated out of the spa cabinet, besides most likely voiding any warranty from the spa manufacturer.

If the equipment is remove from the spa, be sure all components remain properly grounded to avoid a nasty shock - again, better to leave the components inside the spa.

11. Service Access

Thinking about sinking the hot tub into the floor or sealing it up in tile?

Think again, because access to the plumbing parts, motors and other hot tub parts should still be guaranteed in the case the spa needs service or develops a leak.

The best design will include removable panels to access the interior of the hot tub. It is also best to keep the skirting around the spa for energy saving reasons, even if sinking it into the floor.

Also for structural reasons, the portable spa should remain in its original cabinet and access to the cabinet panels should be guaranteed by removable floor boards or removable tile walls etc..

How to drain the spa?
If a floor drain is available, then that is an option, otherwise a submersible pump could be used if the hose was long enough to reach the exterior or a large drain as the spa will need to be emptied about 3-4x per year.

Ideally the spa should be able to be lifted back out of the existing installation in the extreme case of a severe repair that would warrant needing to remove the spa to access and repair the spa properly.

Some homeowners would like to completely recess the spa in the floor, but getting into the spa that way is more cumbersome than if the spa edge is about 13 inches off the ground. This makes for a handy place to sit and swivel into and out of the spa without risking injury. Also testing the water is easier if the lip is at least 13 inches off the ground even if partially recessed.

If this is a new installation during a construction phase, then coordinating between HVAC contractor, the electrician and the builder is essential to assure all code requirements are met. Once the job is done, the indoor oasis can be used 365 days out of the year. So enjoy your spa room indoors.

12. Code Requirements
Just as with Jacuzzi bathtubs, there will be some code requirements for safely installing and operating the electrical appliance indoors. There are sections of the National Electric Code to be knowledgeable of including 680.43 which specifies the minimum distances of electrical outlets and lights to the hot tub bath.

GFCI must be provided not only for the hot tub, but also for power outlets within a certain distance from the hot tub. Wall switches must be at least 5 horizontal feet away from the indoor spa and lights or ceiling fans must be at least 7 1/2 feet above the spa or higher with GFCI protection.So you still want to put the hot tub indoors? Smaller hot tubs will create relatively less problems, but above tips should be considered before installing any spa indoors.

The good news is, if it doesn't work out and the path is still open, the spa can be moved outdoors! But if the above issues are addressed and pros are consulted regarding indoor air quality and placement of the spa, then an indoor installation is definitely a possibility and has been successfully completed thousands of times all around the world.

Check out the 120v plug and play spas that don't require 230v.  The Silver Star is the best 2 person hot tub for this purpose that comes with a hard cover.  Need a bigger one?  We've got them all, as long as you can fit it inside.  Otherwise, a covered porch, deck or gazebo is a great option.

This is not an exhaustive list, but for becoming aware of certain considerations when planning for an indoor hot tub installation. Appropriate professionals should be consulted to assure your indoor hot tub project goes smoothly.

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