Choosing the Best Hot Tub Cover

Your hot tub cover will protect your water from debris, animals, and some airborne bacteria, while also trapping the heat inside and saving you money. Naturally you want to get the most cover for your money. You want a cover that will do the job and last a long time. The following are a few tips for picking out your hot tub cover.

The Fit

Make sure it fits. Your hot tub cover should fit snugly over all sides of the hot tub, and should rest very close to or on the surface of the water. If the sides are loose, then animals could crawl in to get to the warmth or the hot water will evaporate and escape.

If it is too high off the surface of the water, hot water will evaporate, cling to the underside of the cover, then cool and drop back down into the water, lowering its overall temperature. Not to mention that the evaporation and condensation cycle would tend to release or use up the spa chemicals.

Ideally, the bottom of the cover would be on the water surface since that is what we want to keep warm.

Because we have been in this hot tub cover business a while, we have seen every manner of ill fitting, broken, taped, tarp covered, and otherwise “beyond it’s normal life span” attempt to put off getting a replacement cover.

Heavy Hot Tub Covers keep people out of the spa
If your cover looks like this you’re probably not using the hot tub today

This not only looks terrible but it costs you money because all of these efforts don’t really help. If you’re going to drain your spa and get rid of it, fine. But if you intend to keep using it, investing in the right cover is going to help.

The Insulation

Make sure it traps heat efficiently. As we stated before, a hot tub cover that sits up on the edge of the spa, several inches off the water surface, will trap evaporating water and cause it to condense and cool, then fall back into the spa lowering the temperature of the water.

What also occurs is the foam inside a traditional cover absorbs steam because it is a small molecule than water, then the water vapor condenses and becomes trapped in the foam material over time. Once the spaces in the foam have been filled with moisture whatever insulation value it did have is gone. A water logged cover has the same insulation value as a sheet of plywood.

Hot Tub Cover held down with sand bags
If this is how you keep your hot tub cover in place you need a new cover!

The moisture also causes the cover to slowly become heavy until it either can’t be lifted or breaks under its own weight.

It gets worse. One of the other adverse effects of the saturated cover sitting way off the water surface, the cover will freeze when the outdoor temperature is below freezing. Because the outside of the cover is actually in contact with the freezing temperature outside and not in contact with the spa water it becomes a solid block of ice.

From the outside it may appear to be doing a great job insulating because snow will pile up on top of the cover. That’s because snow doesn’t mind sitting on ice. Unfortunately, your spa is working harder than ever trying to keep the spa water heated underneath that frozen cover.

To avoid the spa cover from becoming a solid block of ice over your hot tub in winter, you need to get one that does not sit up on the top of the edge of the spa, several inches off the water surface. You need a cover that won’t soak up moisture and freeze. A cover that will insulate the water at the water surface, like the SpaCap.

SpaCap hot tub cover in winter conditions
SpaCap on duty in winter

Weather Proof

Make sure it’s weather proof. If your hot tub is stored outside and not under shelter, then the cover must be durable enough to withstand rain, wind, snow, and potentially hail or winter precipitation. The cover must also prevent rainwater and wind from getting into the hot tub and cooling down the water.

So you need to have a cover that can keep the rain and debris running off, with a taper or better yet a dome shape

The tapered cover, is usually sold with the idea that it will keep the rain running off and because of that it won’t get heavy. If that were true, no tapered foam filled hot tub cover would ever get heavy. But it isn’t true because the do get heavy.

Every tapered, foam filled cover ever sold will get heavy because the moisture doesn’t come from outside the hot tub. In fact the only way to insure that a foam filled hot tub cover won’t get heavy is to never use it. If you never put it over hot water where steam can infiltrate into the foam it will never get heavy.

So if no foam filled hot tub cover ever made can keep from soaking up moisture once it’s in place over warm water, the solution is NOT to buy another foam filled spa cover, but to get one that does not use foam panels. The SpaCap are the only hot tub covers that won’t saturate.

Let’s talk for a minute about spa cover lifters because a lot of hot tub owners have fallen for the idea that a lifter will be the solution to a heavy cover. But it is not, because every lifter ever made is designed to work with a light weight cover.

Think about it. You still have to flop half the cover over the bar before the lifter is used. In most cases, that first lift is the one that is beyond hot tub owners. But if you did manage to open it halfway and then push the lifter hard enough to move a heavy cover, something has to give.

Either the spa cover will rip itself apart because it can’t hold it’s own weight or the lifter will rip itself off the hot tub cabinet. So a “lifter” is NOT the answer to a cover you can’t lift.

The only hot tub cover that won’t become saturated is the one with no foam. You need a spa cover that uses air chambers to do the insulating instead. The SpaCap.

If your spa cover is trying to make a bridge over the spa, then a heavy wet snow load will crush it. If the bottom of your spa cover rests on the water, it can transfer the weight of the snow and handle almost any snow load. In thirty years of building the SpaCap hot tub covers, and selling them in mountain retreats all over the world, not one has ever been crushed by snow.

If your spa cover has a rigid surface, the wind can eventually lift it off the spa and take it to parts unknown.

The physics of this are fairly simple, wind hits the side of the spa and then goes up and over. As the wind sweeps over the top of the spa it creates a vacuum above the rigid foam cover until it lifts it off the hot tub. Once it does the following wind pushes into the space below the cover and the water surface. As the air rushes in it compresses in the space until it pops the rigid cover up. At that point, lift off has occurred and the hot tub cover has become a wing.

Depending on the strength of the wind the cover can fly for miles.

The reason is that the rigid cover presents a surface that the wind can lift making it a wing.

This is where the natural dome shape of the SpaCap makes all the difference. There is no rigid surface for the wind to create lift. The natural dome shape just redirects the winds harmlessly away. Even Hurricane force winds won’t budge it.

In the past thirty years, hundreds of SpaCap hot tub covers have been sold in Tornado Alley and in areas that get hurricanes. Not ONE SpaCap has EVER flown away. They are the only truly Wind Proof Hot Tub Covers.

Pet Safe

Make sure it’s animal proof. Pets and wild animals are sometimes drawn to hot tubs by their heat, and some very small animals will even try to make their homes inside of a thick hot tub cover. Other animals crawl underneath the cover seeking warmth and end up falling in the water and drowning. Make sure the cover doesn’t allow any space for animals to go underneath it, and make sure it is made of material that animals can’t chew through to make their home.

Let’s face it, no cover is perfectly animal proof. But the SpaCap can handle more animal problems than any foam cover ever could. We used to say that no animal has ever damaged one. But in the last thirty years there have been some persistent creatures. There was a bear in Whistler BC that decided he wanted to take a dip in the spa. There was a raccoon in Bellevue WA that tore one up so he could wash his food. In both cases no traditional foam filled cover would have been able to do better.

All total, far more animals have damaged foam filled spa covers than the SpaCap.

More information about hot tub covers is available at SpaCap.