Hot Tub Insulation: How to Insulate Your Spa


Comparing Hot Tub Insulation

Just like in a house, insulation is what keeps the water in your hot tub at the perfect temperature. If your spa’s insulation is inefficient (either not insulated at all or made using lesser materials), you could find yourself waiting longer for the water to heat up, spending more on energy when the spa is in use, and paying for repairs more frequently due to the increased effort on your parts.


A quality cover is one of the most important parts of your hot tub’s insulation system.

Because it keeps the heat from escaping and the water from evaporating, you should select a cover with care. It should be specifically selected to fit your model and contain a quality, high-density foam core. Refrain from using your cover as a table, convenient as it may be, as this can introduce rips and other damage that can cause your cover to become waterlogged. The center of your cover should be raised above the edges so that water does not pool in the middle.


No Insulation: If you choose to buy an inflatable or a portable “spa-in-a-box” style of hot tub, neither of these options will have insulation. Some models will use the word “insulated” in a product description, but unless you are able to quickly tell what type of insulation is present, it is probably referring to the cover that is included. These types of hot tubs may save you money initially, but will end up costing significantly more in energy bills as you will need to bring the water up to your desired temperature before each use and they will need to work harder to maintain that temperature.

Partial Foam: Partial foam used to be the industry standard and are still sold today due to their cheaper construction materials and reluctance on the manufacturers to upgrade their facilities. Hot tubs that have partial foam insulation will have insulation attached to the inside layer of the hot tub (between the tub itself and the outer wall). This insulation may be sprayed (like in an attic) or rigid foam boards and does not fill the entire cabinet. With this approach, air is a definite problem. The heated air from your spa escapes while simultaneously allowing cold air to come in, requiring more effort to keep your water warm.

Thermal Wrap/Blanket:

Full Foam: Full foam is the new industry standard, replacing partial foam. This method is more energy efficient, allowing you to use less than half of the energy required with a partial foam hot tub and enjoying a more relaxing spa experience. True to its name, spas insulated with full foam will have an inner cabinet that is completely filled with foam. This allows the unit to retain more heat, which means that the components that operate your hot tub will not have to not work as hard. The additional foam cuts down on the vibrations that can come from these components, lowering your chances of needing to call a plumber because a part has come loose. While these models will cost more initially, you will see significant savings compared to the energy loss and repair costs you will encounter with less insulated options.

FiberCor® is full foam insulation system that is completely unique to Watkins Wellness™. Instead of foam that is sprayed in, FiberCor uses a blown-in, wool-like insulation that is made of non-hazardous fiber. These fibers are four times denser than the foam used in other hot tub models and completely fills the inside of your spa, removing any chance for gaps for air to escape and for mold to grow. The material is partially recycled and is easily removeable if repairs are needed. Hot Spring® collections Limelight® and Hot Spot® use this technology. If you are in East Texas, contact us to learn more about these excellent spa options.

Multi-Density Foam: Hot tub manufacturers used to only use a single density of foam when filling the inside of the spas.