Maintaining Your Spa Cover – Preventing Early Failure

by Tony Turbo.

Though your spa cover receives the harshest treatment from the environment, it’s often overlooked in maintaining a great-running hot tub. In the Summer, it’s protecting your spa from intense sunlight & heat. In the winter, its subject to wind, rain, snow, and ice, while preventing your spa from freezing.

Though most spas are insulated with foam in the spa cabinet, it’s actually your cover that provides the greatest insulation, helping to keep your spa water at a relatively constant and warm temperature. So, it surely makes sense to take care of it.

We’ll start “at the top”, what you commonly see, but we’ll end discussing the “bottom” because it’s often issues with the bottom that are the reason spa covers are thrown out sooner than they should be.

Cover Exterior

Spa covers are made with a Styrofoam core and an encasement (the exterior), most often made of vinyl. There are a # of vinyl protectants available. Spraying & wiping a vinyl protectant on your cover’s exterior several times a year will help extend its life.


The interior of your spa cover is Styrofoam. It will vary in both density and thickness. Increasing either also increases the insulation value of your cover. The two most common cover thicknesses are 2” on the side rising to 4” in the center and 3” rising to 5”. The thicker cover is more commonly used in colder areas. The pitch, or rise to the center of your spa cover, is there to ensure that rain will not puddle up and potentially develop enough weight to break the Styrofoam.

Cover Underside (The Bottom)

Properly maintained a spa cover will typically last for 5 – 7 years. When it fails, it is usually because the encasement has become brittle and cracked. However, when a cover fails prematurely, it is often due to issues on the underside, the bottom, of your cover.

It used to be that a common reason for spa cover replacement was it got too heavy. This was caused by the Styrofoam absorbing moisture through the underside when the spa cover was closed. However, this was largely solved with two changes. First you will notice a small “weep” hole in the center of each side of your spa cover. This allows moisture to drain out. More importantly, these days, most cover manufacturers also enclose their Styrofoam cores in plastic before installing it in the encasement. This plastic isolates the Styrofoam from the moist air trapped when the spa cover is down, thereby preventing the Styrofoam from absorbing moisture.

The #1 Reason Spa Covers Fail Early

This brings us to the #1 reason spa covers are trashed prematurely. They develop ugly black mold on the underside of the cover.

You might not think about it, but there are lots of things floating around in the air you breathe. Pollen is one but mold spores are another. Both are more common at some times of the year than others.

We all know that mold just loves warm, moist places. The is the perfect description for the space between the surface of your spa water and your spa cover. When black mold spores are in the air, they are also in the air under your spa cover. Without proper care, you can soon develop black mold on your spa cover and around the pillows in your spa.

Preventing Premature Spa Cover Failure

There are two important steps to ensuring you do not develop black mold on the underside of your spa cover.

First, maintain the proper level of sanitizer in your spa water. However, quite a few spa sanitation regimens like to tout the use of lower levels of chlorine or bromine. Unfortunately, this also results in higher incidences of black mold. (They didn’t tell you that, did they.)

Second, use either SERUM Total Maintenance or SERUM Triple Action Spray. You don’t need to do both. If you are already using Total Maintenance, you will not need Triple Action Spray to prevent black mold. However, if you are not using Total Maintenance, Triple Action Spray will also prevent it.

How Do SERUM Total Maintenance and Triple Action Spray Work?

Both Total Maintenance and Triple Action Spray contain a chemical called Benzalkonium Chloride or ADBAC. ADBAC is lethal to bacteria, viruses, mold, algae, fungus, etc. It’s very effective though also safe for use in spas & hot tubs. In fact, SERUM Total Maintenance is EPA Registered. Used in your spa, both Serum products help ensure your spa cover will last the 5 – 7 years that it should.

Thanks for reading,
Tony Turbo

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