What are the best ICF Blocks for building a Hot Tub?

Best ICF Block

ICF stands for insulated concrete forms, which are blocks made of insulating foam or expanded polystyrene (EPS) that are used to build concrete walls. The foam provides insulation to help keep the hot tub water warm, while the concrete provides structural support and durability.

They are often used in construction because they provide excellent insulation and energy efficiency. The popularity of such ICF Blocks has certainly increased over time and in the last 18 months, I have seen more requests from customers that are looking to build with them.

I’ve even got some case studies on this blog and on my YouTube Channel that showcases ICF Blocks in action.

In this article, I will examine what I think are the best ICF Blocks for building hot tubs, what features you should look for and why.


There are several different types of ICF blocks available, and the best one for your hot tub will depend on your specific needs and preferences. Some things to consider when choosing an ICF block for a hot tub include the size and shape of the hot tub, the climate in which it will be used, and the overall budget for the project.


What is the best ICF Block for a Hot Tub – Cost Factor


Whilst on the surface, ICF would seem considerably more expensive, when you actually break things down it is not as much as you may think.


ICF is definitely more expensive than traditional blocks, however, when you factor in the time savings on the construction side of things, as well as not needing to purchase separate PIR insulated panels, they are not too much more expensive. In my mine, they are worth it.


If you compare them to regular forming methods, as the cost of timber has increased dramatically, you need a lot of expensive timber


What are the 7 benefits of the Best ICF Blocks for Hot Tub construction


  1. Energy efficiency: The foam insulation in ICF blocks helps to keep the hot tub water warm, which can save energy and reduce operating costs.


  2. Durability: ICF blocks are very durable and can withstand the weight and pressure of the water in the hot tub. They are also resistant to extreme weather conditions, making them a good choice for hot tubs that will be used year-round.
  3. Structural integrity: The concrete in ICF blocks provides structural support and helps to ensure the hot tub is stable and safe.
  4. Easy to work with: ICF blocks are lightweight and easy to cut, making them easy to work with during the construction process. This is especially important for us DIYers who often work solo. Lugging round ICF blocks is not a problem at all – they are light and easy to manoeuvre. The same cant be said for CMU blocks!
  5. Soundproofing: The foam insulation in ICF blocks can help to reduce noise, making the hot tub a more peaceful and relaxing place to be.
  6. Environmentally friendly: ICF blocks are made of recycled materials and can be recycled again at the end of their lifespan, making them an environmentally friendly choice for hot tub construction.
  7. Cost-effective: ICF blocks can be a cost-effective option for hot tub construction, as they can reduce the need for additional insulation and may lower energy costs in the long run.

The Best ICF Blocks are Simple


I’m a big fan of keeping things simple. I don’t need an ICF block with a complicated construction method. All I want is a set of blocks that can be quickly and easily glues together to form the shape for my hot tub. Anything else is just an overkill as we are only doing around 3.5 courses, 4 max.


Hot Tubs don’t need the internal structure of ICF


You will find that there are a lot of ICF blocks on the market that have quite a complex internal structure. This internal structure is there and is designed to replace the need for steel rebar. It will also increase the price as the cost of producing this kind of a block is much higher.


If it isn’t broken – don’t fix it! For our Hot Tub builds, we simply do not need this complex internal structure. It is not like we are building a two-storey house or anything like that. Keep it simple. A regular ICF polystyrene form and regular rebar is all we need for our hot tubs.

My Opinion Is…..?


OK, I know, I’m probably a little biased here as TubBlox are my own brand. However, I do think that for the Hot Tub Construction they are the best ICF Block. If we were building a home or a garage, then there are probably better systems out there.


TubBlox are simple, inexpensive, have good R (insulation) value. The internal structure is suited to the DIYer as all is needed is a simple rebar addition. I just don’t see the point in over complicating things.


So, for me, the best ICF Block for building Hot Tubs is TubBlox.


Happy “TubBlox” 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.

Today, I've helped over 1000 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

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