Ben’s DIY Concrete Plunge Pool in Pennsylvania (Case Study)

Last updated: September 2026

A DIY concrete plunge pool? Oh yes!

Ben, in Pennsylvania, USA, set out to build his own concrete plunge pool in his backyard: a place to relax and a project he could proudly call his own. His build had its challenges, but it’s a great example of what a determined DIYer can do.

Ben had a design and he had a plan. What he wanted was reassurance that it would work. The biggest worry we DIYers have is that the project won’t work after all the time, money and effort we’ve put in. So Ben used me as a sounding board for his ideas, and he knew I was on hand to answer any questions along the way. With that support, he could make informed decisions, avoid the common pitfalls and build a plunge pool that exceeded his expectations.

So let’s get started on Ben’s DIY concrete plunge pool.

Planning the plunge pool

Ben’s journey started with careful planning. He knew a DIY concrete plunge pool needs more than ambition, so before picking up the tools, he ran his plans past me.

I always say that if you fail to plan, you plan to fail. Planning is a key part of the design process, and if you’re thinking about building your own concrete plunge pool, you must have a plan. It’s something I can help with, either with off-the-shelf plans or a custom design consultancy. My DIY plunge pool guide is a good place to start.

Breaking ground

With a solid plan in hand, Ben moved on to the exciting part: breaking ground. He marked out the area carefully, allowing for the size of the plunge pool plus the extra space needed to build it.

As the dig went on, Ben paid close attention to the depth and shape of the hole. The floor and walls had to be built to precise dimensions, and a level, well-prepared base was crucial for the structure and for the pool to work properly.

Forming and pouring the floor and walls

With the excavation complete, Ben turned to forming and pouring the floor and walls. He used sturdy formwork to shape the concrete, so the structure would be both sound and good-looking.

He measured and marked the positions of the plumbing and other fittings before pouring. The floor came first, and he made sure it was perfectly level to give a solid foundation for the rest of the pool. For more on rebar, see my rebar guide, and for floor drains, Installing a main drain.

Form time

Next came the walls. Ben paid close attention to keeping them a consistent thickness and finish. The walls of a concrete plunge pool aren’t only structural, they’re a big part of how it looks, so every step matters. If you’re weighing up poured walls against other methods, see Alternatives to gunite and shotcrete and Hot tub wall construction: what are the options?

Before the pour, Ben built the plumbing into the walls. That gives the circulation and filtration the pool needs and allows for spa jets too. Setting every pipe and fitting in place before the concrete goes in gives a neat result, and it’s far easier than cutting into the walls later. My DIY plumbing guide covers the layout, and How to install gunite jet bodies covers the jets.

As Ben worked through the forming and pouring, he knew I was on hand with any questions.

With the floor and walls poured, Ben was well on his way.

A genius addition: the dog grate

One feature of Ben’s plunge pool stands out as truly ingenious: the “dog grate”. Pool safety matters for pets too, so Ben came up with a clever way to make the pool safe for his dog.

The custom grate reduces the pool’s depth in one area, so his dog can jump in and out without any worries.

Waterproofing and finishing

With the structure complete, Ben moved on to waterproofing and the finishing touches.

First, he waterproofed the concrete with a specialist coating to protect the structure and give a durable surface. Then came the looks: a tiled waterline, and pool paint on the interior for a smooth surface that’s easy to look after. My waterproofing, tile adhesive and grout guide covers the products I’d look at, and Hot tub tiles covers waterline tiles.

The end result? Absolutely fantastic!

Congratulations, Ben

Ben’s plunge pool shows what vision, determination and thoughtful design can do. Congratulations to Ben, who handled the challenges of the build and added clever touches like the dog grate along the way. A big thank you for all the pictures too, Ben.

It proves that a simple design, done well, can make a backyard haven that goes beyond expectations. Nice job!

Planning your own plunge pool?

If you’re torn between a plunge pool and a hot tub, have a read of Hot tub vs plunge pool: which should you build? In the USA, remember that an in-ground pool usually needs a permit (see Do I need a permit?) and equipotential bonding (see What is ground bonding?).

My plunge pool plans come in several sizes, including 12ft x 8ft, 14ft x 7ft and 15ft x 8ft, each with architectural drawings in imperial and metric. If you have your own design like Ben did, my custom hot tub (or pool) design consultancy or architectural CAD and 3D plumbing design will check it works and draw it up properly.

FAQs

Can you build a plunge pool from poured concrete?

Yes. Ben’s is formed and poured, with rebar in the floor and walls. The plumbing needs to be in place before each pour, because cutting into cured concrete later is hard work.

How do you waterproof a concrete plunge pool?

Use a pool-rated waterproofing coating or membrane on sound concrete, then your finish, whether that’s tiles, paint or plaster. Fill and check for leaks before the final finish goes on.

Can I build a plunge pool without a contractor?

Many people do, like Ben. A good plan and someone to check it with make the difference. Leave the electrics to a licensed electrician.

Would you add a dog grate to yours? Let me know in the comments below. I read them all.

Cheers,
Andi

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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