Types of Hot Tub Insulation

There are all manners of different insulations that manufacturers use. We’re going to look at the following three, and their pros and cons:

  • Full Foam

  • Partial Foam

  • Insulated Wrap


You’re probably well aware of expanding foam, available in spray cans for filling and insulating cavities in your home. Foam inside a hot tub is very similar but, on an industrial level.

Once a hot tub has been completely manufactured, the cabinet is filled with closed cell expanding foam, completely covering the shell and pipework (leaving space for components such as your pumps and spa packs).

As you can imagine, this is an excellent insulator and does wonders at keeping your spa warm. However, it has its downsides.

Should you have a leak or issue with your spa that needs repairing, a significant portion of your insulation will need to be dug out so that pipework can be accessed.

Once this foam has been removed it becomes difficult to replace to the same standard as it would in the factory.

This foam will also absorb water over time, meaning it becomes less efficient at insulating, and gets extremely heavy, putting pressure on your pipes, and cabinet (and if you ever need to move the spa, good luck!).


Realising full foam has its complications further down the line, a lot of manufacturers turned to partial foam. The shell and it’s pipework are wrapped in a clingfilm type material to support the pipework, and then this wrap is sprayed with a thin layer of foam. The result ends up being a hard shell around the interior of the spa.


Example of partial foam taken during a repair

The above photo is a great example of partial foam filled hot tubs but, its also a fantastic example of why partial foam can be troublesome.

In order to minimise the amount of foam used, a lot of the pipework is condensed into a small space around the spa. Should you have a leak or issue with the spa in the future, the foam ‘shell’ has to be cracked open, which becomes difficult to replace, and the pipework and spa supports are all so tightly packed, it can be difficult to access the necessary areas to carry out repairs, without having to remove a significant amount of foam.


Insulating wrap solves most of the above issues, while being a fantastic insulator. Hydropool hot tubs are triple wrapped with this insulation to tackle the icy cold winters of Canada. This makes them a fantastic option for the UK.

The layers of wrap support the pipework, in the same way the two foam options do, without the risk of absorbing water.

Should you need repairs, the insulation is simply cut open or removed, and can be taped, stapled and replaced without any change or loss of insulation.

It can be good as an insulator as 8-10 inches of foam, it is long lasting and easily maintained/repaired.

While it may not be as great of an insulator as completely filling the spa cabinet with foam, it provides and excellent balance of accessibility, insulation, and also breathability during the Summer months. Your pumps get very hot when working - and when the temperature outside is 30 degrees, it can lead to overheating. Insulating wrap can allow the pumps to get just the right amount of airflow.

See Our Article About Energy Efficiency in Hydropool Hot Tubs to Learn More.