I Love It When a Plan Comes Together: Rob’s Custom DIY Hot Tub (USA)

Last updated: September 2026

“I love it when a plan comes together.” Anyone spot the 1980s TV reference? It’s the A-Team, probably my favourite programme as a child, and maybe, dare I say it, how I got into the whole DIY thing. I always marvelled at the contraptions the A-Team cobbled together. I loved making things as a kid, and I still love making and creating things today. I vividly remember playing A-Team with my younger brother. I was always Hannibal Smith, the man with a plan.

Perhaps some things don’t change. I’m still the man with the plans. They’re just hot tub ones now.

Anyway, enough about my childhood. In this post we’re looking at Rob from the USA and his custom DIY hot tub build.

Every single time this happens, I still get a huge smile on my face. It’s the moment I get a text, WhatsApp or email showing me a finished tub. A tub that started out as a bunch of lines in CAD on my computer has been turned into reality by a happy DIYer at the other end of the message. “You made it possible!” Rob’s message read. I feel a huge sense of pride every time I read something like that, as another hot tub DIYer leaves the proverbial nest. That feeling will never get old.

My A-Team moment came when Rob sent me a picture of himself in his finished tub with a big cigar. Very Hannibal Smith. I could almost hear those famous words. But like all great projects, this one started with a plan.

Background

Rob got in touch through the website with a clear idea of what he wanted. My off-the-shelf designs weren’t going to fit his space or his vision, so he asked me to create a custom design for him. That was “the plan”. If you’d like to know what that involves, I’ve explained it in Custom designed hot tub: the process explained.

As you can see from the design images below, the idea was L-shaped seating with jets on one side only. That was because of the path on the other side, where there just wasn’t the space. Rob was also very clear that he had a view, and when you see the photos further down, you’ll see he does indeed have a view to frame. That hot tub certainly does it.

The design

As with all my custom projects, the design goes back and forth until the customer is happy. We got there pretty quickly with Rob, because he had such a clear vision. Next came the plumbing design, then the parts.

If you’re working out your own layout, What makes a good DIY hot tub design? and Top tips for designing the ultimate DIY hot tub are good places to start. You can also sketch your space in the free Tub & Pool Designer Pro software.

Parts supply

I also supplied the parts Rob needed. Like most of my customers, he added his own pipe. It’s much cheaper to buy locally than to ship, and PVC cement is a chemical, so carriers often won’t take it. For what to buy, see Hot tub pipe: the ultimate guide and How to make the perfect PVC solvent weld joint.

The key to a good DIY hot tub is the right plan and the right parts to go with it. Knowing you’ve got the right parts and just have to put them together in the right order makes life so much easier. Put them in the right order and it’s not that they might work. They are going to work. For us DIYers, that’s a big comfort. The full list for a typical build is in my DIY hot tub shopping list.

The build

The stages of Rob’s build are really no different from the other case studies, or my own build, that you’ll find on the website.

If you’re building with block like Rob, you dig a hole, lay a slab, build the block walls, core some holes, fit the plumbing, add some tiles, fill it and enjoy! Sounds easy, doesn’t it? Of course, each stage is a lot more involved than that, but that’s the journey every DIY hot tub takes. For the detail:

• Dig, base and walls: How to build a DIY in-ground hot tub
• Plumbing: DIY hot tub plumbing: jets, pipe sizes, drains and the skimmer
• Jet bodies through the wall: How to install gunite jet bodies

Waterproofing, then tiles

Once the plumbing is in and the blockwork is complete, you need to waterproof the structure. There are many ways to do it. Rob used a paint-on sealant from a good hardware store, which is relatively inexpensive and works really well.

What I’d recommend: I used to be happy with a hardware store sealant, but having seen many more builds, I’d now choose a membrane that’s specifically rated for pools and submerged use, such as Laticrete Hydro Ban in the USA or Ardex S 7 Plus in the UK and Europe, applied exactly as the data sheet says. Then do a flood test before you tile. It’s far easier to fix a leak now than behind finished tiles. There’s more in Waterproofing, grout and tile adhesive.

Tiles can be a challenge, depending on the type you choose. I went for large tiles on my own build, so I had the same problem as Rob: cutting holes for the pipes. I can’t remember how many tiles I cracked, but I know it was quite a few. I love the cutting rig Rob put together. It holds the tile in place while he uses a pillar drill to core a perfect hole. Genius!

I’d steer most people towards mosaic pool tiles, which make fittings and curves much easier. See Hot tub tiles: everything you need to know.

The end result

Simply stunning. What a fantastic build. Rob, you’ve done a superb job.

I love it when a plan comes together!

Now do you get the A-Team reference?

What Rob’s build teaches us

• Know what you want. Rob’s clear vision made the design quick.
• Design around the space. Jets on one side only was the right answer for his path, not a compromise.
• Frame the view. Decide where you’ll look from the seats before you fix the layout. Hot tub privacy ideas and Hot tub deck ideas cover the surroundings.
• Buy pipe locally and get the specialist parts from one supplier who knows they fit together.
• Make a jig if you’ve got lots of holes to cut in tiles.

Want a plan of your own?

If one of the standard sizes fits your backyard, my DIY hot tub plans give you CAD drawings with every dimension, the plumbing layout, a full parts list and the video course.

If, like Rob, a standard plan won’t fit your space, sketch it in Tub & Pool Designer Pro and I can turn it into architectural CAD and a 3D plumbing design. If you’d like me with you from design to completion, as I was with Rob, take a look at my custom hot tub design consultancy.

Planning your own build? Tell me about it 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