How to Pour a Concrete Slab for a Hot Tub

Do you want to make a comfortable and secure hot tub area in your backyard? A concrete slab is an excellent foundation for any hot tub, allowing it to sit levelly while providing a solid base. While building your own concrete slab may seem like an intimidating task, the process can actually be quite straightforward.

How to Pour a Concrete Slab for a Hot Tub

In this blog post, we’ll walk through the steps of how to pour a concrete slab for a hot tub that will serve as the perfect support system for your new hot tub. Keep reading and get ready to pour yourself some peace of mind!

What Kind of Concrete Is Used for Hot Tubs?

When it comes to pouring a concrete slab for your hot tub, the type of concrete you use is extremely important. Standard concrete is usually not strong enough for a hot tub area and can be damaged easily over time by moisture and temperature changes.

Hot tubs require the use of specialized concrete known as “high-strength” or “high-early strength” concrete. This type of concrete contains a special mix of materials that makes it stronger and more resistant to damage, making it the ideal choice for hot tubs.

High-strength concrete is typically more costly than regular concrete, but its superior strength and durability make it well worth the additional cost. It should also be noted that high-strength concrete typically has a longer curing time than regular concrete, so you’ll need to plan ahead and factor in this additional time when pouring your hot tub slab.

Additionally, the instructions on the bag of high-strength concrete should be followed carefully for best results.

When it comes to pouring a concrete slab for your hot tub, it’s important to make sure you use the right kind of concrete. High-strength or high-early-strength concrete is designed specifically for this purpose and should be used whenever possible. It may cost a bit more than regular concrete, but its superior strength and durability make it the ideal choice for hot tubs.

Be sure to read and carefully follow the instructions on the bag of concrete mix to ensure a successful outcome.

With proper preparation and the right kind of concrete, you can have a safe and secure base for your hot tub in no time at all!

9 Methods How to Pour a Concrete Slab for a Hot Tub

1. Choose the Right Location

To Choose the Right Location

The first step in pouring a concrete slab for a hot tub is to choose the right location. The location should be level and well-drained. It should also be close to an electrical outlet, as hot tubs require a lot of power to run.

If you’re planning on burying the hot tub in the ground, be sure to choose a spot that will make it easy to access. You should also avoid any areas with tree roots, as the roots may interfere with the concrete slab. Although pouring a concrete slab may seem like an easy job, it should not be taken lightly.

2. Excavate the Area

Once you have chosen the location, you will need to excavate the area. The excavation should be about 6 inches deep and should be slightly larger than the hot tub itself. If you are placing the hot tub on a flat surface, then it is best to dig out an area that is slightly larger than the base.

This will ensure that the hot tub is level when placed on the concrete slab.

Once you have excavated the area, use a tamper or a hand tamper to make sure the bottom of the hole is even and smooth. This will prevent uneven areas in the concrete slab, making it easier to level the hot tub. If you are putting a pad down, then make sure that it is also even and smooth.

3. Install a Vapor Barrier

After you have excavated the area, you will need to install a vapor barrier. This will help to prevent moisture from seeping into the concrete and causing it to crack. You can use a 6-mil polyethylene sheet or other suitable material. Lay the vapor barrier all over the bottom of the excavation area and up the sides.

To Install a Vapor Barrier

If you are using polyethylene, use rubberized asphalt tape or masonry nails to affix it to the sides of the excavation area. Make sure to overlap the edges of each sheet by at least 8 inches. This will ensure that moisture won’t be able to travel between them. Once you have the vapor barrier installed, you are ready to start pouring the concrete for your hot tub pad.

4. Pour the Concrete

Once the vapor barrier is in place, you can begin to pour the concrete. The concrete should be at least 4 inches thick and should be poured into sections so that it can cure properly. Fill each section with enough concrete to be slightly higher than the edges of the vapor barrier. Use a spud bar to spread and level out the concrete.

Then use a bull float to smooth out any ridges that may have been created. Finally, use an edger to round off the edges of the slab. Once the concrete has been poured, you must wait a minimum of four days before installing the hot tub. This will allow the concrete to cure and take on its proper shape.

Make sure to keep the concrete damp during this curing period. This will ensure that it doesn’t dry out too quickly, which could lead to cracking. After the concrete has cured, you can begin the process of installing your hot tub.

5. Install Rebar

After the concrete has been poured, you will need to install rebar. Rebar is a type of steel that helps to reinforce concrete and prevent it from cracking. It should be placed at least every 2 feet around the perimeter of the slab. Push the rebar into the wet concrete, making sure that it is completely covered.

You can use a hammer to tap it into place if needed. If you are pouring a large slab, consider using additional rebar in the middle of the slab as well.

6. Cover with Soil

You Are Using a Screed

After the rebar has been installed, you will need to cover the entire area with soil. This will help to insulate the concrete and keep it from getting too cold or too hot. Make sure the soil is spread evenly across the entire area. Once this has been done, you can begin to pour the concrete slab.

If you are using a screed, make sure you have it ready before you begin pouring the concrete.

It is important to ensure that the slab is level and that it has an even thickness across the entire area. Once you have poured the concrete, use a trowel or other tool to smooth out the surface. Then, you can use a broom to give the slab a textured finish. Finally, allow the slab to cure for 24 hours before proceeding to the next step.

7. Cure for 28 Days

After the concrete has been covered with soil, you will need to let it cure for 28 days. During this time, it is important to keep the area moist so that the concrete does not dry out and crack. You can do this by using a garden hose to lightly mist the area daily. After 28 days have passed, your hot tub slab should be ready for use.

Congratulations, you have successfully poured a concrete slab for a hot tub!

8. Remove Soil and Vapor Barrier

After 28 days have passed, you can remove the soil and vapor barrier from around the slab. You should then clean up any debris that may have been left behind during excavation or installation. If there is any dirt or dust left, you should sweep it away.

You can also use a garden hose to rinse the area and remove any remaining residue. Make sure the ground is completely dry before proceeding to the next step. Although the area must be dry, you should not use any heat sources, such as a blow torch, to speed up the drying process.

9. Install a Hot Tub

After the slab has been prepared, you can then install your hot tub on top of it. Make sure that your hot tub is level so that it does not cause any damage to your concrete slab over time.

Connect All of the Necessary Pipes

Once you have the hot tub in place, connect all of the necessary pipes and wires to ensure a safe and enjoyable experience. Finally, fill your hot tub with water and any desired chemicals, and you’re ready to enjoy your hot tub!


Now that you know how to pour a concrete slab for your hot tub, all that’s left is to enjoy it! This project requires some heavy lifting and time, but it will be worth it when you can finally relax in your own backyard oasis. Be sure to follow the instructions on how to pour a concrete slab for a hot tub carefully and reach out for help if needed – once the slab is set; there’s no turning back!

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