Guy Builds Hot Tub & Plunge Pool Combo From Scratch!

If you’re a fan of DIY hot tubs and cold plunges, you’ll love this new project by Patrick from Wisconsin, USA. Patrick is in the process of building a semi-in-ground, semi-above-ground hot tub and cold plunge combo. His build features poured concrete construction, built-in jets, and a sturdy plumbing system—and I’m tracking every step of his journey.

So keep reading on to find out whether Patrcik managed to get this DIY hot tub and cold plunge up and running!

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The Start of Patrick’s Build

Patrick kicked things off with an off-the-shelf hot tub design from my store. These designs have been tested thousands of times and come with video tutorials, parts lists, and everything needed for a seamless DIY build. Not every project I show is custom-designed—many DIYers use my pre-made plans to bring their build to life.

Not only did Patrick get the blueprints from my store, but he also ordered all the parts through it. This gave him a streamlined starting point, reducing the guesswork often involved in DIY builds. 

Dry Fitting: The Essential First Step

Before diving into full assembly, Patrick dry-fitted everything—a crucial step when working with hot tub plumbing. If you’re unfamiliar, dry fitting means assembling all the pipes beforehand without glue to check measurements, alignments, and fit. This ensures that once you commit with glue, everything is positioned perfectly. This also saves you from any last minute mishaps since you know everything already fits. 

Once Patrick was satisfied with the layout, he moved on to the next critical phase: building the forms for the concrete pour.

Constructing the Forms & Pouring Concrete

The hot tub and cold plunge sit side by side, and since Patrick’s build is semi-in-ground, he started by digging down before constructing the bench seating and tub bases.

Because this is a poured concrete build, Patrick had to secure all plumbing within the forms before the concrete was poured. That meant:

• Gluing the pipes together after dry-fitting
• Tying the pipes to the rebar to keep them stable
• Capping off the pipes to prevent debris from getting inside

Capping pipes is a simple but often overlooked step—it keeps dirt, gravel, and other construction materials from clogging the system before it’s sealed.

Bracing the Forms: A Must-Do

If there’s one thing you cannot afford to overlook in a concrete build, it’s properly bracing your forms. Patrick made sure to reinforce his wooden forms with strong bracing, preventing the weight of the wet concrete from bowing or distorting the walls. If your forms bend under pressure, you’ll end up with crooked, non-perpendicular walls, which is a nightmare to fix after they’ve set. 

Pro tip: If in doubt, add extra bracing—concrete is incredibly heavy, and it’s always better to over-support than under-support.

The Big Pour: Locking in the Foundation

With everything set up, Patrick poured the concrete and left it to cure for several days. Once the curing process was complete, he removed the forms, revealing a solid foundation with pipes securely embedded within the concrete. This marks a significant milestone in the build.

What’s Next?

Now that the lower portion of the hot tub and cold plunge is complete, Patrick needs to let the concrete fully harden—a process that takes one to two weeks. After that, he’ll move on to building up the backs of the seats using concrete blocks.

Of course, we’ll be tracking the entire process right here, so subscribe to the channel and stay tuned for the next update on Patrick’s DIY hot tub and cold plunge project!

Final Thoughts

This build is a perfect example of how a DIY hot tub can be both achievable and high-quality. By using a tested design, careful planning, and smart construction techniques, Patrick is on his way to creating an awesome at-home spa experience.

And as always, Happy Hot Tubbin’!

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi