Do I Need a Hot Tub Insulation Pad?

hot tub insulatrion pad lg

So, you just ordered your first hot tub, or maybe yours is just not very energy efficient, and now you’re wondering, “do I need a hot tub insulation pad?”

Here’s what I’ve learned:

As a general rule, an insulated pad for a hot tub is not necessary except for inflatable hot tubs. However, hot tubs being placed on decks could benefit from an insulated pad to prevent heat loss through the deck boards.

In this article, I look at the alternative types of pads and their uses. When you absolutely need an insulated pad under your tub and when it really isn’t worth the effort.

To find out what is best for your situation, read on.

Is a hot tub pad necessary?

A stable and level hot tub pad is necessary for the structural integrity of the hot tub frame and shell. Otherwise, stress fractures could occur due to uneven weight distribution.

That being said, if you have a flat concrete back patio that is totally level, there’s no reason it couldn’t just sit directly on the concrete.

Pavers also don’t necessarily require an additional pad.

If you have a plug ‘n’ play hot tub – the type you plug into your regular outlet – the chances are it is not very well insulated, and you will find that an insulation pad is great at reducing heat loss through the ground.

The same applies to inflatable spas (see more on this below).

Timber decks and gravel surfaces can damage the base of your hot tub if you have to drag it around to position it. Additionally, with decks, there can be heat loss both since it’s off the ground and since there are gaps in between the deck boards.

So, an insulated pad is a good idea in those cases too.

If you’ve placed your hot tub on a concrete base, which I highly recommend, you probably don’t need a pad underneath the tub, but it will help in other ways.

A hot tub pad will reduce noise by isolating the tub from the surface underneath as it can minimize vibrations.

There are other ways of reducing noise – in fact, I wrote a recent article on this topic, and you can read it here on my site by clicking on the link.

The main cause of hot tub noise is vibration, so the more you can reduce this, the quieter it becomes. Vibration comes from the pump, so when this kicks in during the night to circulate the water, it can potentially be quite a nuisance to any nearby neighbors.

If you can’t do anything about vibration, you can mask the noise.

A universal compressor sound blanket can reduce the noise from the pump by around 5dB. This may not sound a lot, but because of the nature of sound, a reduction of 3dB almost halves the sound intensity, and 5dB by almost 70%, so this will make a difference.

Is a hot tub pad necessary for an inflatable hot tub?

A hot tub pad, ideally an insulated one, is essential for inflatable hot tubs. It helps protect the underside from puncture and also prevents heat loss into the ground.

Inflatable hot tubs are a great introduction to the world of spas and Jacuzzis, but they have their faults. Number 1 is, they don’t hold the heat in very well.

With only two layers of vinyl and around 18 inches of air between them, there isn’t much to stop the heat from escaping through the sides. And even if the tub comes with a lid, these are usually thin and poorly insulated.

But don’t despair; there are things you can do to improve this, particularly if you want to use your hot tub in the cooler months. One of them is to place the tub on an insulated pad or groundsheet.

First off, you need to make sure you have a firm base on which to sit your hot tub in. 

Now, your hot tub doesn’t have to sit on a concrete base. In a recent article, I pointed out the alternatives, which you can read about here on my site by clicking the link.

But the key thing is to provide a sturdy level base.

Having prepared your base, lay your insulation pad over this and install your newly arrived hot tub. If you are concerned about heat loss, take a look at your lid. Is it the best you can get? Does the retailer have better alternatives?

If you went for the cheapest, you might want to reconsider if you intend to use your hot tub in wintertime.

As for the walls, aside from encasing your tub in insulating material, there’s not much else you can do. But hey, this is your first foray into hot-tubbing – next time, you can upgrade to something better.

How do you insulate the bottom of a hot tub?

Improve the insulation to the bottom of a hot tub by placing it on an insulated mat or pad. But for existing hot tubs, the best option is to use spray foam insulation to all reachable areas once the side panels are off.

Cheap hot tubs are generally not well insulated when they leave the factory.

This is because most people look at the size and number of jets and then, of course, the price. Insulation just doesn’t have that wow factor.

At the low end of the market, the hot tub cabinet is only partially filled with insulation, which is usually a urethane spray foam on the shell of the tub. To improve on this, you can either add more foam or use a thermal wrap, either inside or outside the cabinet.

More expensive hot tubs have full-foam insulation that fills the whole cabinet, including the pump and plumbing.

This helps make the hot tub more energy efficient while reducing vibration and noise. There’s nothing more you can do to improve on this.

So, if you’re adding to the insulation, here are a couple of don’ts:

  • Don’t use spray insulation on the motor. This gets hot, and it needs to be able to lose that heat, or it will burn out.
  • Don’t spray over any controls or other things that you might need to access for maintenance.
  • Don’t cover the vents in the cabinet. These are there for a purpose.

Is it worth moving an existing hot tub to insulate underneath?

It can be worth moving an inexpensive plug ‘n’ play hot tub that is likely poorly insulated to place an insulated pad underneath. However, for most hot tubs, the benefit gained from a pad is really not worth the effort. 

There are other things you should look at to improve the insulation and reduce heat loss from your hot tub.

But it is certainly advisable for inflatable hot tubs, which can easily be moved once drained. In the section above, I mentioned foam insulation and thermal wrap, but what is the best?

If it is purely down to how well the insulation retains the heat, foam insulation is by far the most efficient, but thermal wrap, which can be in the form of rigid Styrofoam or polystyrene, is more convenient if you want to fix it inside the cabinet.

The lid is where you lose most heat, and this is one of the easiest fixes.

If you want to save yourself some money on running costs, invest in a new, well-insulated lid but make sure it’s the right size for your hot tub.

A good, tight fit is essential.

If you want to read more about the types of insulation for your hot tub, check out this recent article. I got into the best ways to add insulation, and I included a step-by-step walkthrough of what I did to my hot tub.

Just click that link to read it on my site.

What is the best insulation pad to put under a hot tub?

The best after-market insulated hot tub pad is the Confer SP3248 Handi Spa pad. But many hot tub manufacturers, particularly in the inflatable market, supply mats to suit their own brand. Made to fit the exact size of the hot tub, these are often the best pads to go for.

CLICK HERE to see the Confer pad on Amazon.

Some are flexible mats, providing insulation but little structural support. Others are rigid interlocking tiles that make up the size and shape you want.

But if you’re looking for that bit of extra rigidity and perhaps a larger area to cover, there are a few alternatives available that are worth considering.

As I mentioned, one that I love, and it does have some excellent reviews, is the Confer SP3248 Handi Spa on Amazon. Made from high-density polyethylene resin, this pad comes in convenient 32” x 46” sections that are easily clipped together to form a base virtually any size you want.

The pads are durable, waterproof, and so rigid, you don’t even need a concrete base.

Just an area of flat, even, and firm ground will be enough to support your hot tub. I would still recommend concrete pavers or compacted gravel at least. Certainly not on sand – your hot tub will sink into it!

The packaging seems a bit odd, though. You get 3 in a pack – that’s not even square! So, you will need 2 packs to cover an area of 8’ x 8’ and 3 packs for 8’ x 12’.

Did I cover all you wanted to know about using a hot tub insulation pad?

It won’t do any harm sitting your hot tub on an insulating pad, but the benefits are much greater on smaller, poorly insulated tubs and inflatable spas.

Pads vary from flexible mats to rigid panels, so I hope in this article you’ve learned enough to decide what is best for you, and even if it’s worth installing a pad at all.

If there is anything I’ve missed, just leave a comment or drop me a line, and don’t forget to check out those links to related articles here on my website.

Jeff Campbell

Jeff Campbell is a husband, father, martial artist, budget-master, Disney-addict, musician, hot tub lover, and recovering foodie having spent over 2 decades as a leader for Whole Foods Market.

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