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Does a Hot Tub Need to Be Level? (Yes, here’s how & why)

By: Author Jeff Campbell

Posted on  - Last updated:

Categories Hot Tub Installation

Many first-time hot tub buyers are unsure of where to put their new hot tub. And the most common question they ask is “does a hot tub need to be level?”

Yes, a hot tub needs to be level. Most hot tubs are made of a wood frame under an acrylic shell. While they are designed to hold thousands of pounds when full of water and people, they are built to distribute that weight evenly. If a hot tub is not level, that can cause stress fractures in both the wood and the shell.

But there’s a lot more to know about hot tubs, where to place them, and how to get them level.

So in this article, we’re diving deep into hot tubs and the best things to place them on.

Maybe you’re unsure where you should place yours? Or maybe the ground underneath your hot tub has shifted over time, and you need to figure out what to do about it.

Have no fear, this article will inform you of all you need to know to determine where to place a hot tub or fix where your hot tub is now.

There are a few things you should determine before installing your hot tub.

  • Where will you be placing your hot tub?
  • How large is your hot tub? Many hot tubs range from 78 to 84 inches in diameter
  • Square or rectangular hot tubs can have diameters of up to 110 inches

Keep on reading to figure out where and how to place your hot tub or how to fix one that is no longer level!

Does hot tub have to be perfectly level?

Yes, is the short answer. Maybe not perfect down to the millimeter, but it needs to be pretty level.

For outdoor hot tubs, it is common to place hot tubs on surfaces such as decks and patios made out of both concrete or brick. In fact, hot tubs can be placed on any uniform, solid, level surface.

But the hot tub must be on a level surface.

A dip in the surface your hot tub is on can cause the hot tub to crack. Additionally, do not place your hot tub directly on the grass.

In general, it should never be placed on the bare ground at all.

You can use pavers on top of the grass, or dig up the grass, level the yard, and use gravel as a support base for the hot tub.

When placing your hot tub on a surface such as a wooden deck, you should be aware of the weight of the hot tub (especially when filled with water and occupants) and the amount of weight that the deck can hold.

I have my current hot tub on my back deck. But that part of the deck is reinforced to take the weight.

Not sure if your deck can take the weight of a hot tub?

No problem. I break it down simply and easily in a recent article. I explain how to calculate whether your deck can support it. But I also cover how to reinforce yours if needed.

Just click that link to read it on my site.

For the placement of an indoor hot tub, any regular floor that is code compliant works perfectly fine.

Basement concrete floors that are level will also work.

If you wish to place a hot tub on a porch, check to make sure that it can adequately support the weight. If you are installing the hot tub indoors, be mindful that ventilation is required. Moisture from the hot tub can damage walls, furniture, carpeting, and ceilings.

To work around this, just make sure that you have installed a ventilation exhaust fan either above the hot tub or in a side window.

How do I level the ground for a hot tub?

Before leveling the ground, there are a few considerations.

The first step is to select a good site for the hot tub. The area should be one that gets good drainage. This is so the hot tub will not be surrounded by puddles or mud.

The second step is to check the area you have chosen. Make sure there are no overhead power lines. Additionally, make sure no trees or shrubs are not close by; you don’t want those roots to grow under the hot tub.

That could later cause it to be unlevel.

You also want to make sure that the chosen site would not block your access to your septic tank, sewer lines, or any other utilities.

Next, make sure the site of the hot tub is close to a water source that can refill it if needed.

A hose should always be nearby. You will always want your hot tub at least five feet away from an electrical panel or outlet.

But you also don’t want it so far from an outlet or panel that it costs a fortune to run the power to the tub (been there, done that). Some hot tubs plug into outlets, and some require electricity connected by an electrician.

Once you have done all this, you can begin to level the ground.

Do this by removing bumps and filling up holes. Use a shovel and a hoe to do this. Remove rocks and other large debris. Also, make sure that there are no tree roots where you wish to place your hot tub.

Remember, the ground must be smooth and level.

Next, place a layer of gravel on the future site of your hot tub. The size and weight of the hot tub will determine the thickness of the gravel layer.

A layer of four to six inches will be sufficient for most hot tubs. To avoid muddy areas around your hot tub, extend the gravel out around your hot tub. Then compact the gravel to make it a smooth surface.

Congratulations! You are ready to place your hot tub.

Can you shim a hot tub level?

You can absolutely shim a hot tub level.

For many people, tearing up the patio/deck/concrete slab their hot tub lies on and replacing it with a level foundation is not a financial option. This is where shims come in handy.

The majority of hot tubs come with shim points. Look at your owner’s manual and it will inform you of where they are and how to do it.

However, some hot tub brands do not support shimming. Additionally, there have been incidents in which after a few years the shims rot. So for that reason, I recommend NOT using wood shims.

My favorite shim is these heavy-duty plastic shims from EZ-Shim.

Believe it or not, they are about 10 bucks on Amazon for a set of 20, qualify for free shipping, and can take the weight of a hot tub. Just click that link to grab a set on Amazon if you need to shim.

The hot tub I had at my last house, which I bought used, ended up not sitting level once I put it in place.

I had placed in on pavers that looked level, but I didn’t do a good enough job of verifying before I brought the hot tub into the back yard.

I ended up using a series of shims to get it more level, and that worked just fine.

Just be aware to not over-shim as you don’t want to place too much pressure on either the wood frame (mostly 2×4’s) or the acrylic shell. That could lead to cracking.

So, shim to make minor adjustments only.

Does a hot tub have to sit on concrete?

No is the short answer.

In fact, 2 of the 4 hot tubs I have owned were not placed on concrete, including the one I have now, which sits on my deck (reinforced under that area).

Concrete is, however, the most stable of the options. It’s also easy to ensure that it’s level, and there’s no denying its ability to support the weight of a large hot tub crammed full of people.

But if concrete is too expensive, or there’s not an easy way to get a concrete truck to the area you want the hot tub in, here is what you need to consider:

  1. Do not place the hot tub on grass or bare earth
  2. You can place it on a level pad made of stone pavers
  3. Get a spa pad made out of heavy-duty plastic. 
  4. Gravel beds are great for outdoor hot tubs. The gravel conforms to the hot tub base and will hold it in place.

I mentioned spa pads there, which you may not have heard of.

Basically, those would take the place of pavers or concrete and are far less costly. You would start by using a shovel to get a patch of ground level. Then add fine gravel or sand and place the spa pad on top.

It may be plastic, but it can take the weight!  And unlike loading up 60 or so stone pavers into your car from Home Depot, these things only weigh 15 pounds total for an 8’x8′ pad, delivered to your door for free from Amazon!

CLICK HERE to see my pick on Amazon.

As long as the surface is uniform, solid, level, and can support the weight of the hot tub, you have lots of options.

Remember to include the hot tub filled with water and occupants in your calculations) then you are all set to go.

Not sure how to calculate the weight of your hot tub?

You’re not alone! Luckily, I take the mystery out of figuring that out in one of my recent articles. I get into everything from figuring out not only the weight of the tub but also people and water weight (the biggest factor).

Just click that link to figure out yours quickly and easily.

What happens to a hot tub if the ground is NOT level?

If the ground is not level for your hot tub, it could crack.

Over time, an unleveled hot tub will put excess stress on the shell and wood frame. The frame (mostly 2×4’s) and shell are designed to hold the pressure of the water and people spread out across a wide area.

But when the hot tub isn’t level, that can put excess pressure in concentrated spots; more pressure than either the shell or framing is built to take.

So over time, the frame under the shell can crack and/or you may get stress fractures in the acrylic shell.

Additionally, the water level will be off, with one side of the hot tub holding a higher amount of water than the other.

Simply put, you need a solid, level foundation for your hot tub!

Anything other than that will cause you to spend more money on fixing the issues that come with an unlevel foundation. It will also shorten the lifespan.

Not sure what the lifespan of an outdoor hot tub is?

They can last up to 20 years. But poor maintenance, or not leveling your hot tub can shorten that significantly.

In a recent article, I cover all the best tips you need to know to get the longest life possible out of your hot tub. What really surprised me was how much the water chemistry being off can shorten the lifespan.

Just click that link to read it on my site.

Final Thoughts

In this article, we took a deep dive into the world of hot tubs and what a proper foundation for one is.

We examined different types of foundations, from pavers to concrete, decks, and even plastic hot tub pads. We also explored shimming and how that can help get it level if it has shifted over time.

An unlevel foundation can cause your hot tub to crack.

So ultimately, we answered the question “Does a hot tub need to be level” with a definite yes.

If you’re just installing your first hot tub, another common question is whether or not you need a fence around yours.

Just to make it more confusing, there are Federal, state, and local laws to be aware of and even CDC guidelines! Luckily, I take the mystery out of it in a state by state guide which answers all your questions.

That way you can be safe and legal with your new hot tub. Just click that link to read it on my site.

Photo credits which require attribution:

Couple relaxing in the hot tub at Forest Holidays by Forest Holidays is licensed under CC2.0

As an Amazon Associate, I may earn a small commission from qualifying purchases if you click on Amazon from my site and choose to make a purchase. You can read my complete affiliate disclosure for more details.

Jeff Campbell
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