ByRossi

The base for the hot tub is a vital element in the installation. A hot tub should not be placed directly on the ground or grass. If the pad under the tub is flat and solid, then the tub will last you for many years and will not break.

In this article, we will look at what are the options for bases, the advantages of each, and tell you how to build them.

A place to build a base for a hot tub

Let’s figure out how to choose a place outdoor to install a hot tub because it plays a crucial role in its further use and durability.

It is very convenient to install a hot tub close to the house. Because it will be comfortable for you to go out and come in, wipe yourself off and not freeze outside on chilly days. You can also use steps for easy entry and exit. There are many different types, and it can be difficult to decide which stairs are best for your needs. In our guide to hot tub stairs, we broke down all the nuances of choosing the right ones and told about how you can build them yourself.

Also, do not forget about electricity and water supply. If they are all in the house, you should install the hot tub near it as laying external communications can be expensive. This arrangement is the most popular.

The next thing to consider when choosing a location is drainage. The hot tub can overflow when too many people get into it, and thus the water will overflow around the base. To keep it from stagnating, you need to choose the right place on the elevation or has natural drainage.

It is also significant to consider the placement of the neighbors. It is unlikely that you will be able to relax fully with other people in the neighborhood. The hot tub should be in a more private location. And possibly with a good view of nature.

Try to choose a place for the hot tub where it will be protected from wind and sunlight. If you live in an area with a hot climate, place a tub in the shade. Or at least where there is shade during the hottest part of the day. And there are special umbrellas and other hot tub accessories on the market to protect your hot tub from the sun, rain, dirt, and leaves.

Hot tub base options

Regardless of where you decide to place the tub, you should consider that it will have an extreme weight when filled with water. And if you add a full complement of people to it, it can weigh up to about 600 pounds. That’s why it’s so important to provide a sturdy base for a hot tub. 

There are many different types of hot tub foundations, including concrete, gravel, decking, and pre-made. Each has its advantages and installation methods.

Concrete

Concrete is a versatile material for all purposes because of its strength and durability. For many hot tub owners, concrete bases are the preferred option because they are economical and functional. It provides strong weight support. 

The advantage is that such a concrete base is not difficult to make with your own hands. The height of such a base should be at least 10 cm and ideally be reinforced with rebar. It should be on a firm foundation or rubble to create a good base. It should also be able to withstand at least 115 pounds per square foot, especially if you have a large hot tub.

There are several options for installing a concrete base for your hot tub. You can make the foundation slightly larger than the area of the hot tub and then build a deck or something similar around it so you can walk on it. Or you can extend the concrete beyond the hot tub to create a sturdy environment. If you are worried about how it will look, you can also add trim around the bottom if there is visible concrete that you find unsightly.

The advantages of concrete are that it is easy to level. It is also an environmentally friendly material.

Gravel

A base of gravel is also an excellent option. It has the same strength as concrete but also has good drainage properties. Unlike the other options, this option is more permeable but still provides the necessary support and bearing capacity needed for the hot tub.

Also, gravel is not expensive material. You can use any crushed stone or gravel. But in addition, you will need to build a square-shaped frame of wood or stones to hold the gravel. If you choose wood, it should be made of pressure-treated timber and treated with wood protection. Such a frame will last 2 to 4 years. The ground beneath the base must be level and dense. 

Gravel base construction is the easiest option to install and maintain. But some people may not like the look of ordinary gray gravel. In this case, you can buy decorative stones and cover the top layer with them. 

Decking

This option is the most beautiful and elegant and will fit into any interior. Also, the hot tub terrace is the most pleasant of all variants in terms of feeling for the feet.

If you already have a terrace, you should consult with an engineer about whether it can withstand the weight of the hot tub. The decking can be reinforced with reinforced materials or concrete supports.

Pre-made base

There are dense rubber panels available on the market for a hot tub base. If you don’t have the time or desire to build your decking or concrete foundations, this option is just for you. Prefabricated foundations will save time but not money. They cost anywhere from $100 to $600 depending on the manufacturer. 

For this option, you need to dig a level surface on the ground and thoroughly tamp it down. The panels are then interlocked to each other and laid into the ground the size of the hot tub base area. Then all the voids in the panels are filled with gravel or pebbles. It creates a solid base for the hot tub.

Which hot tub base option is right for you?

The best base for a hot tub depends on your personal preferences, the space you have, and your budget. 

A concrete base	It is a universal option in almost all cases. Concrete is a strong and durable material. In most cases, manufacturers recommend installing hot tubs on such a base.  The only thing with this option is that you can not easily change the location. And also, concrete does not claim to be the most aesthetic option, but you can always decorate it.
A gravel base	It is also a durable option as well as easy to install. Concrete over time, with improper installation, can crack, but with crushed stone, this does not happen. Also, crushed stone has good drainage.
Decking	Placing a hot tub on a deck is an attractive way to showcase it. In addition, it is convenient to get in and out of the spa under your feet. However, when building a deck from scratch, this is one of the most expensive hot tub bases. It is also the least durable option.
Pre-made base	Pre-made pads are also hard-wearing and won’t crack like concrete. They can be a temporary option for a hot tub base. It makes them the perfect choice if you live in rental housing or are unable to make permanent changes to your habitation, or if you want to take your spa mat with you when you move.

How to build a concrete base for a hot tub🔨

Step 1. Level the place where the hot tub will be installed.

Step 2. Remove the topsoil layer in the area where the base will be, at the size of the frame. But don’t dig deeper than 4 to 6 inches to keep the ground firm.

Step 3. The next step is to build the frame. It should be larger than the size of the tub, so add an inch to each side of the hot tub, which is the size the frame should be.

Step 4. Secure the frame to the ground with wooden stakes so that it is stable and will not move out of place while the concrete is being poured. Be sure to check the level of the frame! This is crucial to the proper installation of the hot tub. 

If you prefer, you can put a layer of gravel on the bottom of the frame, about 4 inches.

Step 5. Next, mix the concrete according to the instructions and start pouring it into the frame. Make sure that the concrete is poured into the corners and that there are no voids. 

Step 6. Level the surface of the concrete using a 2-inch by 4-inch bar. Move it back and forth across the surface of the slab to remove excess concrete, thus ensuring a level surface.

You need to wait two days for the concrete to dry and remove the wooden frame. Note that the tub cannot be installed immediately. You must wait 28 days for the concrete to dry completely and be stable.

How to build a gravel base for a hot tub🔨

Step 1. Level the place where the hot tub will be installed.

Step 2. Remove the topsoil layer, about 2-4 inches, so that the earth is firm and will not settle.

Step 3. Post a wooden frame. Use pressure-treated 4×6 lumber designed for contact with the ground. The size of the frame can be anything, as long as it is larger than the size of the hot tub. 

📌For the frame stability, we recommend drilling holes around the perimeter and inserting ½-inch diameter reinforcing rods into the wood and the ground. 

Step 4. Lay sturdy landscape fabric around the perimeter of the frame on the bottom. This will provide extra support and prevent weed growth.

Step 5. Fill in 4 inches of medium-grade gravel. Smooth out by hand or with a vibratory plate and rake to make the surface level.

You can also add 2-3 inches of fine gravel on top to finish the base.

How to level a hot tub?

If the surface under the hot tub is not leveled, it can crack. The body of the tub is designed to distribute the weight evenly. And over time, if the hot tub is not leveled, an excessive load is put on one part of the body and can not withstand and crack. 

An important part of the hot tub level is the preparation of the land before installation. Carefully inspect the site and remove stones and other large debris. Make sure there are no tree roots. After that, remove any irregularities and fill holes, if any. 

If you need to adjust the level of the hot tub after installation, you can use shims in that case. Some manufacturers provide a set of shims as part of the hot tub. In this case, you can use the enclosed instructions for their proper use. You can also buy heavy-plastic shims separately. We do not recommend using wooden ones, as they will rot over time. 

Summary

Before installing, you need to choose the right place for a hot tub, where there are all the necessary communications and where you will be comfortable taking a hot tub. After that, the chosen site should be leveled, remove stones and other debris, and make sure there are no tree roots nearby. Take a shovel and remove the top layer of earth about 2-4 inches thick. 

After this preparation, you need to choose one of options to build a hot tub base — concrete, gravel, boards, or pre-made. Choose based on your aesthetic preferences, budget, and capabilities. Each option has its place.

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