Which Foundation Is Best for a Hot Tub?

Once you purchase a hot tub, your main focus may be enjoying the hot water, luxurious jets, and bubbles. However, before your hot tub is delivered, there’s something you can’t afford to overlook – the foundation where the spa will be installed

While you may think installing your hot tub on the grass or dirt in your backyard is fine, this would actually be a huge mistake. Before delivery, you need to ensure the right type of foundation is in place and ready to go. 

Unsure what type of foundation is right for your yard, unit, or needs? If so, learn about some of the top foundation options for your hot tub here. 

Why Is the Right Foundation for Your Hot Tub So Important?

Before reviewing the top foundation options for your hot tub, you need to understand why it’s so important. 

First, you have to consider the weight of the hot tub. Even if you purchase a smaller unit, it will weigh thousands of pounds once it is filled with water. Keep in mind that a single gallon of water weighs 8.34 pounds. This means that the standard 400-gallon spa will have 3,336 pounds in water weight alone – this doesn’t factor in the tub itself. 

Because of this, if you have a hot tub that weighs several thousand pounds, there’s no way it will sit evenly on a dirt or grass surface. Instead, it will wind up sinking into the ground and may ruin your yard and surrounding landscape. 

It’s also important to think about the damage that will happen to the hot tub itself if it is installed on a dirt or grass surface. Even in drier climates, the lower layers of the soil in your yard stay moist. As time passes, the moisture will cause serious damage to the structural integrity of your hot tub. 

Even though your hot tub is designed to hold water, the exterior surface isn’t designed to stand up to extended water exposure. Now that you understand the importance of having the right foundation for your hot tub, it’s a good idea to learn about some of the top foundation options to consider. 

Top Foundation Options for Your Hot Tub

The top foundation options for your hot tub include:


Your existing patio is a great option for hot tub installation. It will also look nicer if you can find a way to tie the unit into your existing landscape features. While this is true, before installing the unit, you need to check a few things. 

For example, is the patio level? If it has even a slight angle or slope, it won’t provide the solid base that your spa needs. You should also consider if the patio has weather damage or age cracks. These may also impact the stability of your hot tub. 

If your patio is not completely level, but this is where you want to have the hot tub installed, it’s time to engage in some maintenance. Sometimes, this will require professional assistance; however, once the patio is level and free from any damage, you can move forward with the installation. 


Installing your hot tub on a deck is also a popular option. With a deck, your hot tub base is already in place. 

While this is true, you still need to have the deck inspected and evaluated by professionals before trying to install a hot tub on it. It’s important to understand that not all pre-existing wood decks can support the weight of a full hot tub. 

You need to figure out the total weight capacity of your deck. In most cases, you will need to reinforce the deck using extra joists and additional framing. It is best to leave this type of work to the professionals. While you can opt for a DIY approach if you have prior experience in construction, this isn’t recommended for those who don’t. 

Concrete Base

Chances are you have heard of both cement and concrete hot tub bases. Cement is an ingredient in concrete, along with an aggregate (i.e., gravel, sand, or rock) and water. While it is more expensive than just gravel, you will still find that concrete bases for hot tubs are still quite affordable. Even better, they are durable and long-lasting. 

After the concrete base is complete, you don’t have to give another thought to it for a while. 

The process used to create a concrete base is simple. It involves starting with an excavated area in your yard that is large enough for your hot tub’s base. However, you won’t need to go too deep; just four inches will be enough in most cases. 

The next step is to use two-inch by four-inch boards to build your frame inside of the pit. After the frame is in place, you will cover the bottom of the pit using approximately an inch of sand. Once in place, pour the needed concrete over it. Using a concrete board and then a bull float, you can smooth out the concrete (while it is still wet). After that, use a trowel on the surface. Only do this once the concrete has begun to set. 

If you don’t want to do this on your own, don’t worry. You can hire professionals to handle the installation of a concrete or cement hot tub foundation for you. 

Paver Stones

Another popular option for your hot tub foundation is paver stones. These are durable, affordable, and beautiful. They are also available in various patterns, textures, sizes, styles, and colors. Pavers provide you a custom foundation solution that is quick and easy to install. There is also plenty of room for your creativity. 

These are quite useful for larger or smaller areas. There are other benefits offered by using paver stones, as well. For example, permeable pavers are an eco-friendly option. They are also durable and provide you with the benefits of design flexibility. This isn’t something that the other foundation options offer. 

Crushed Gravel

Gravel is another affordable option, and it offers constant drainage. Because of this, gravel is a popular option for many hot tub owners. 

While gravel is a great option, you should remember that you can’t just pour gravel on your lawn and think the foundation is ready to go. To have a high-quality, effective base for your hot tub, you must calculate the total amount of ground space the hot tub requires. Once this is done, mark the required space out in your yard to ensure it can accommodate the unit. Be sure to add a few extra inches to each side just to make sure you have plenty of space. 

Once you have the foundation marked, you can dig a six-inch deep pit in the marked area. You need to make sure the bottom is as smooth and level as you can get it. 

Use landscape cloth in the base of the pit and then fill the initial four inches with medium-grade gravel. The top layer should be smaller-sized gravel, like pea gravel. Use a rake to smooth out the surface. At this point, the foundation is ready for the installation of your hot tub. 

How to Choose the Right Foundation Material for Your Hot Tub

It’s important to evaluate your needs and options when choosing what type of foundation to use for your hot tub. While each of the options above has pros and cons, you need to find one that will work for you, your needs, and your budget. 

If you aren’t sure which foundation option best suits your yard and landscape needs, consult with the professionals. They can visit your home or property and help you decide what foundation option is best.

Keep in mind; most people will have a specified budget for their hot tub. Be sure to factor in the cost of the foundation you choose to find the one that best suits your needs. It is also important to consider how the hot tub will be used. After all, if you want a space to relax outside the spa, installing it on a patio or deck may make the most sense. After all, you can add seating nearby, a fire pit, and other amenities that make sense for your outdoor space and needs. 

Contact Our Team at Sundance Spas Kitchener-Waterloo

The foundation material you choose for your spa matters and impacts how well it works and lasts. If you don’t have the right base that is properly installed, level, and secure, you will experience any issues with your hot tub over time. 

Contact us if you aren’t sure what foundation to use or need help with the installation process. Our team at Sundance Spas of Kitchener-Waterloo is here to help. We can provide advice, service, and maintenance solutions for all types of spas and hot tubs available today. We will ensure your hot tub is installed on the proper foundation to ensure you can enjoy countless years of fun and relaxation. 

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