Should You Insulate a Hot Tub Pad? (How and What to Use)

You love that your hot tub allows you to take a dip when the weather gets cold, but sometimes the water isn’t as warm as you were hoping for. A buddy of yours successfully insulated their hot tub, which has you wondering if you should do the same. Should you?

Insulating a hot tub can reduce vibrations and noise, lower your heating costs, and boost heat retention. The best options for insulating a hot tub are foam tiles, rigid foam board insulation, spa pads, or reflective insulation.

In this guide, we’ll tell you everything you need to know about insulating a hot tub. By the time you’re done reading, if you’re interested in adding insulation to your hot tub, you should know exactly how to do it.

Internal components of hot tub that includes the blower, heater, and pump
Inside a hot tub shows insulation | Credit: Natural State Pool and Spa

Why Insulate Under a Hot Tub?

Insulation doesn’t grow on trees, so deciding to insulate your hot tub will require additional time and expense. Higher-quality hot tubs already have insulated shells, but inflatable and cheaper hot tubs are often not insulated.

The benefits you can enjoy besides simply warmer water make it worth it though, we think!

Let’s look at those benefits now.

Fewer Vibrations and Noise

Sitting in a hot tub is supposed to be relaxing. When you turn all the jets on high in your hot tub, you feel like you’re lounging beside a Boeing 747 about to take flight. The vibrations are off the charts.

All the whirring and humming of your working hot tub can also take you out of the moment. You just want to hear the bubbles and the soft music you have playing in the background.

Insulating your hot tub has a twofold benefit for you. Firstly, you’ll deal with far fewer vibrations as the insulation absorbs more of them. No longer will you feel your hot tub vibrate, shake, and rattle as you use it.

The sounds of your hot tub are also quieter so you have more peace when soaking and lounging!

Decreased Heating Time

How much time and money do you spend heating your hot tub now? Do you wish it could be less?

If you’re like most hot tub owners, then the answer is yes, absolutely. However, you don’t know how to reduce your heating time, so you just grin and bear it.

Well, not anymore! Insulating your hot tub also carries with it the added perk of reducing your heating time. Insulation retains the heat for much longer, which means less heating time is needed. 

Reduced Heating Costs

Do you know what else is great about giving your hot tub heater a rest? You can also save money! The less time you spend heating your hot tub, the lower your utility bills will be month after month.

Increased Heat Retention

The heat retention abilities of insulation are why so many households in regions with cold winters insulate their properties. If your hot tub retains more heat, that’s yet another reason to spend less time heating the water.

Related Reading: How Long Does It Take to Heat a Hot Tub? (and Tips for Faster Heating)

Should You Insulate the Sides of the Hot Tub Too?

We’ve established the myriad of benefits of insulating the bottom of your hot tub. That has you curious if it’s worth it to insulate the sides of the hot tub as well.

You can if you’d like, yes! High-quality hot tubs already have insulation.

We’d recommend insulating the walls of your hot tub as well as the bottom if you live in a very cold climate and you like your hot tub water to always be warm.

If your hot tub is on the older side and vibrates or otherwise makes a lot of noise, then it’s also a good candidate for wall insulation.

Other Considerations When Insulating a Hot Tub

Before you decide definitively whether you want to insulate your hot tub, be sure to check out these considerations.

Mold

Some insulating materials are mold-resistant, but not all. If yours isn’t, then mold can begin to develop in the warm, damp crevices of your hot tub.

That will put a damper on your spa use in a hurry. You shouldn’t just ignore mold, after all. The conditions that created it will keep on creating it and perpetuate its spread.

Further, it’s not great for people to breathe in mold. If you already have asthma, allergies, or any other lung irritation, the fungi can exacerbate these conditions.

Even those with healthy lungs might notice they have congestion, an itchy throat (or nose and eyes), very dry skin, sneezing, postnasal drip, and/or coughing after mold exposure.

Leaks

There’s also a misconception that insulating hot tub pipes prevent them from ever leaking.

While it would be nice if that was true, PVC pipes and hoses eventually wear down over time and thus leaks could happen. That’s the case if your hot tub is insulated or not.

Leaks introduce water where it’s not supposed to be, which exacerbates the mold issue described above!

Materials to Use to Insulate a Hot Tub

Should you decide to proceed with insulating your hot tub, we next want to discuss the top materials for doing it.

Foam Tiles

First are foam tiles, which are by far the easiest means of insulating your hot tub. The tiles are like puzzle pieces that interlock to create a large foam surface for insulation.

Just place the tiles on any flat surface such as your hot tub deck and you’ll begin to enjoy the above benefits of an insulated hot tub.

We recommend the BalanceFrom EVA interlocking tiles. You can choose from tiles that are 24, 48, 96, or 144 square feet.

BalanceFrom Puzzle Exercise Mat with EVA Foam Interlocking Tiles, 1/2" Thick, 48 Square Feet, Black

Each tile is half an inch thick and available in two colors, bright blue and black. The high-density, double-sided EVA foam promotes a non-slip surface, and installation of these foam tiles truly couldn’t be any faster.

Rigid Foam Board Insulation

The second type of insulation to consider for your hot tub is rigid foam board.

Rigid foam board is insulating sheathing that comes in one-inch or two-inch thick footboards. The size of each board is either 4×8 or 4×10.

The thermal protection of rigid foam board insulation is its top characteristic. This form of insulation is also adept at being a moisture and air barrier.

You can select from different R-values for rigid foam board insulation, with an R-value representing the insulating ability of a material.

The higher the R-value, the better the insulation. Thus, while rigid foam board insulation with an R-value of 6.2 does suffice, ideally, if you get an R-value of 12.4 or 15.5, that’s a lot better.

You may need to check the weight capacity of this board before laying it down.

Spa Pads

The next option for insulating your hot tub is to use a spa pad.

A spa pad is like interlocking foam tiles in that the pad is comprised of interconnecting tiles. The shape and size of a spa pad are designed to accommodate hot tubs.

The average thickness of a foam spa pad is half an inch, so they’re no thicker than foam tiles. You can also shop for a spa pad in ¼-inch thickness if you’d like.

We suggest the CosySpa hot tub spa pad, which includes 21 tiles that you can interlock. There’s also an additional smaller pad for your hot tub pump to rest on.

CosySpa Hot Tub Flooring Protector - Spa Floor Mat | Hot Tub Accessories | Foam Ground Sheet for Outdoor Hot Tubs | Interlocking Patio Tiles Outdoor | Hot Tub Mat (1/2" Thickness)

Reflective Insulation

The last type of insulation to consider for your hot tub is reflective insulation.

Covered in a layer of engineered foil, reflective insulation is one of the best thermal insulation types you can buy.

The insulation will lessen radiant heat gain and can even redirect escaping heat so you lose less of it in your hot tub.

This roll of reflective insulation should be enough for your hot tub. It will reflect up to 95 percent of radiant energy and won’t lose efficiency if exposed to moisture or humidity.

INSULATION MARKETPLACE SmartSHIELD -3mm 24inx10Ft ReflectiveINSULATION Roll, Foam Core Radiant Barrier, ThermalINSULATION Shield - Engineered Foil

The sound-deadening abilities of this reflective insulation are also going to interest you as a hot tub owner.

Should You Put Insulation Under an Inflatable Hot Tub?

Perhaps yours is an inflatable hot tub. Like a Bestway Lay-Z-Spa, Coleman, or Intex type. Maybe you wanted to try the hot tub life but you’re not sure if you’re ready to commit to a Jacuzzi yet.

If so, then you should absolutely add insulation in the form of foam pads underneath your blow-up hot tub.

Foam pads will prevent the ground temperatures from rising through the inflatable material and making your water cold. Many users have commented on the heat retention benefits of insulating under their blow-up hot tubs and spas.

Further, the insulation acts as an additional protective layer so your inflatable hot tub is less likely to pop. And if that’s not enough, it will feel softer and much more comfortable on your feet.

Related Reading: What to Put Under an Inflatable Hot Tub?

Should You Insulate Hot Tub Pipes?

Wrapping hot tub pipes with foam sleeves or pipe insulation is a wise idea as well, especially if your hot tub is installed in a very cold region.

When the hot tub isn’t in use, through a combination of using a hot tub cover and insulating the pipes, they’ll be far less affected by the cold.

This will retain more heat in cold weather and help prevent cracking or splitting of pipes should they freeze.

Related Reading: What To Do If You Add Too Much Muriatic Acid To Pool

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