How to Pour a Concrete Slab for a Hot Tub

One of the hardest steps in buying a hot tub is choosing where to install it in your yard. Weighing up to 6,000 pounds when filled, a hot tub requires a strong and reliable foundation to support it. Luckily, concrete slabs are the perfect base for your hot tub and are straightforward enough to pour yourself. 

To pour a concrete slab, you first must frame the area with wood boards. Secure them well, then excavate six inches into the ground. Add a layer of gravel, then pour the mixed concrete. Screed the concrete, so it is level, then let dry.  

Pouring a concrete slab for your hot tub will be much easier if you’re familiar with using concrete and power tools or know someone who can help you. Though any novice can have a go at it all by themselves, pouring a slab can get tricky and is better done as a two-person job.  

How to Pour a Concrete Slab for a Hot Tub

Having a stable foundation for your hot tub ensures that you can safely entertain. When placed on an unstable surface, like grass, your hot tub may sink or shift, therefore compromising its security and making it unsafe to use. A concrete slab is a great option because they are custom made to fit your hot tub’s size and can support heavyweight. 

To pour a concrete slab, you will need to have the following items to get started: 

• Shovel
• 2-by-4 wood beams 
• Wooden stakes 
• Ready-mix concrete 
• 3 inch Screws 
• Electric Saw
• Electric Drill 
• Tape measure and level

Once you have your tools and materials prepared, it’s time to pick where you want to place your slab. Make sure to check with your local building department to verify if you need a permit before starting your project. It’s also important to choose a level area of land to build on. 

After you have prepared your plot of land, it’s time to get started. Grab a friend, and follow these simple steps to pour a concrete slab for your hot tub: 

• Step 1: Stake out the circumference of the slab. Generally, hot tub slabs are less than 10 feet by 10 feet but base your decision on the size of your hot tub and the location. Excavate the location but don’t dig deeper than 4 to 6 inches, as a stable, concrete slab requires solid soil beneath it for stability.

• Step 2: Measure and cut your wood beams to fit the area. Assemble them into a frame by screwing two 3 inch screws into every corner. The inside dimensions of your frame should match the exact size that you want your concrete slab to be. If the size is even slightly off, readjust your frame.  

• Step 3: Secure the frame on the ground with wooden stakes to ensure it is stable and won’t move during the rest of the pouring process. Using your level, verify that the frame is even before you being to pour any wet cement. Double and triple check, as this step is crucial to a successful cement pour.  

• Step 4: Dump a 1 to 2-inch layer of gravel or sand into the bottom of your frame. Now, prepare your ready-mix concrete according to manufacturer instructions. Pour the mixture into the form, making sure to push the concrete into the corners and to tap along the edges to release air bubbles. 

• Step 5: Screed and flatten the surface of the concrete by using a 2-by-4 inch beam. Slide it back and forth as you move across the surface of the slab to remove excess wet concrete and ensure a level finish. 

• Step 6: Now, the easy part: sit back and wait for the concrete to dry! You should wait at least two days before you remove your frame and an additional 28 days before you place your hot tub on the slab to ensure it is dry and stable. 

Where Should I Place my Concrete Slab?

Choosing where to place your hot tub and concrete slab can be more difficult than actually pouring the concrete. It’s important to keep in mind that placing the hot tub too close or too far from your house can be problematic. Its also important to consider how level an area of ground is before you choose, as uneven ground will require extra work.

Choosing a location with a good drainage system is one of the most important aspects of picking where to place your slab. You will have to perform frequent maintenance on your jacuzzi, including fully draining and cleaning it a few times a year. Overflow from use is also common. Place your hot tub by a drain, or install one if needed. 

When choosing your spot, make sure not to place your hot tub or slab too close to your home. The steam and moisture from the tub may seep into the windows, and the walls promoting mildew and rot. You should also be sure to place it at least 12 feet away from any overhead cable and telephone lines or light fixtures. 

Keep in mind that placing it too far has its disadvantages too, most obviously that if you live in a colder environment, it may deter you from using your hot tub at all. You should also consider where your hot tub will get its power from; placing it too far from your house may limit your options and make it complicated to power.

Determining where to place your concrete slab is a crucial part of hot tub installation and of maximizing your enjoyment and relaxation. You should always check with your local building department for a professional opinion to ensure the safety of your equipment and the placement of your tub. 

Preparing the Ground for Concrete 

Once you have chosen a spot, and before you begin pouring your concrete, it’s important to ensure that the ground is prepared for a concrete pour. To do so, visually inspect the area for holes or bumps. If necessary, fill in the holes and level the ground with a shovel and hoe before pouring. 

Its also important to look out for tree roots, whether underground or above the surface, and large rocks. They can disturb the stability and evenness of the ground, which can cause major problems with the pouring of your slab and the installation of your hot tub. Avoid areas with tree roots, and remove any large stones before pouring. If you have uneven concrete, there’s still a way you can work around it to have your hot tub sitting level.

Summary 

A concrete slab is an excellent foundation for your hot tub. A slab can easily support the weight of your jacuzzi and guests, is waterproof, and can be built to the exact size that you desire. Pouring a slab is also cheap and straightforward if you know what you are doing. 

When building a concrete slab, it is extremely important to be precise in your measurements, especially when building the frame of your slab. Precisely measuring your excavation depth and the amount of gravel or sand you place in the base of the frame is also crucial to successfully pouring your concrete. 

Overall, pouring a slab of concrete can be completed in a few hours with the help of a friend. Compared to a deck or grass, it is more stable and will hold up great to general wear and tear. It’s low maintenance and won’t break your bank account, too, so what are you waiting for? Your new hot tub oasis is just one concrete slab away. 

There are plenty of hot tub to choose from, if you’re more interesting in more affordable hot tubs, be sure to checkout our list of the best inflatable hot tubs we could find!