Knowing when to replace a hot tub cover can be tricky. Today we will explore how you can tell when it’s time to change your cover, what to look for in a replacement hot tub cover, and how to properly maintain your cover to extend its lifespan. But first, why do hot tub covers need to be replaced in the first place?
Why Do Hot Tub Covers Need To Be Replaced?
Simply put, hot tub covers are less and less effective over time. As they become less effective, more heat is allowed to escape the hot tub and your heating costs increase. Over time, these increased heating costs outweigh the cost of replacing the cover and it only makes sense to replace the cover.
Hot tub covers are essentially large pieces of foam covered first with a thin plastic vapour barrier and then in a thicker vinyl skin. The actual insulating is done by the foam. The vapour barrier then protects the foam from taking on water and the vinyl skin protects both from the UV of the Sun.
Over time, the chemicals in the hot tub wear down the vapour barrier surrounding the foam and the foam begins to take on water. Once the foam starts to take on water it dramatically reduces the hot tub cover’s ability to insulate.
Foam insulation works by trapping warm air within the bubbles of the foam. Since water is a poor insulator (water transfers heat 32 times faster than air), if those air bubbles fill with water the cover loses much of its insulating ability. This causes a dramatic increase in your monthly electric bill, especially in the winter.
How Long Do Hot Tub Covers Last?
In general, hot tub covers have a lifespan of around 4-5 years. UV radiation from the sun, falling debris (like tree branches or ice), heavy snow loads and user inflicted damage can all drastically reduce this lifespan however.
When Should You Replace Your Hot Tub Cover?
Most hot tub covers need to be replaced when their foam core becomes saturated with water. How can you tell when a hot tub cover has become saturated with water? It will start to get heavy; in some cases heavy enough that the centre seam begins to split when you try to lift the cover. If not replaced the cover can even become too heavy for one person to lift.
Another sign a hot tub cover needs to be replaced is if water starts to pool on it. This is a sign that the cover has begun to “cup”. Hot tub covers can start to cup when subjected to heavy loads – often from snow or ice loads, or from people sitting on them – over long periods of time.
Another way you can tell if a hot tub cover has cupped is to check its corners. If the corners of the hot tub cover have started to lift away from the hot tub shell, the cover has started to cup.
Like covers saturated with water, cupped hot tub covers are a problem because they greatly reduce the energy efficiency of the cover. Rather than reducing the efficiency of the foam, cupped covers instead break the seal around the edge of the hot tub, allowing a substantial amount of steam and (more importantly) heat to escape. This leads to a higher energy bill, more water needing to be added (and heated), and more money spent on balancing chemicals.
Buying A New Hot Tub Cover
Once you know that it is time to replace your cover, the question becomes what to look for in a replacement hot tub cover. Knowing what cover to purchase can be tricky as most retailers offer many different options at many different price points.
Here are a few essential things you should look at when buying a new hot tub cover.
How Good Is The Stitching?
Poor stitching can result in the cover ripping, even under normal use. Look for heavy thread and multiple lines of stitching in the seams.
How Thick Is The Foam?
When it comes to the thickness of the foam, the thicker the cover, the better it will insulate. Replacement covers can be anywhere from 3″-2″ thick up to 6″-4″ thick. Thicker hot tub covers are also heavier though.
Once thick hot tub covers become waterlogged they put even more stress on both the seam of the cover and the cover lifter. This means that thicker covers usually don’t last quite as long as thinner covers will. The added insulating ability of the thicker cover can therefore negated by having to buy a new cover sooner. Overall, we’ve found that covers between 4″-3″ and 5″-4″ thick tend to be a good compromise between energy efficiency and lifespan.
Does The Cover Have A Full Foam Sealer?
A full foam sealer (aka full hinge seal or baffle seal) is a piece of insulating foam that fills the area between the two sides of a hot tub cover. Without a full foam sealer, your new hot tub cover will have a 1″ gap that is not insulated when the cover is closed, leading to a huge energy loss.
What Is The Thickness Of The Vapour Barrier?
As we previously mentioned, the vapour barrier is what stops water from absorbing into the cover’s insulating foam. Vapour barriers in replacement hot tub covers typically range in thickness from 2ml to 10ml. The thicker the vapour barrier, the better it will stop water from absorbing into the foam, and the longer it will last before deteriorating.
Hot Tub Cover Maintenance – Do’s And Don’ts
Before we end this article, we thought we would share some of our top hot tub cover do’s and don’ts. Following these tips will help you get a longer life out of your hot tub cover.
- Do: Use the hot tub cover’s built in clips to lock the cover down and prevent it from being damaged by high winds. Clipping the cover down will also form a better seal, reducing the amount of heat loss and increasing the energy efficiency of the hot tub!
- Don’t: Rest anything heavy on your cover. As we’ve seen, heavy loads can cause your hot tub cover to cup over time. Remove any heavy loads of snow or ice in the winter and try to avoid sitting or placing anything on the cover.
- Don’t: Use shovels to remove snow from your hot tub cover as their blades can catch on the cover and tear open the vinyl skin and vapour barrier.
- Do: Leave your cover fully open for at least 30 minutes after shocking your hot tub. After you shock your hot tub, strong chemical vapours are released that can harm the underside of the cover and increase the rate at which the vapour barrier deteriorates.
- Do: Make sure that your water is properly balanced. Acidic water can stretch out the fabric on the underside of the cover. Consistently high levels of chlorine or bromine can also degrade the vapour barrier and foam of the cover.
- Do: Clean your cover using a UV protecting spray at 2-4 times a year. This will help to reduce the harmful effects that the Sun has on the vinyl finish of the cover.
- Don’t: Place your hot tub in spots where large amounts of snow and ice can fall and damage the cover.
- Do: Try to place your hot tub in spots that are sheltered from prevailing winds. Strong winds can lift the cover slightly, breaking the insulating seal that they form with the shell of the hot tub and increasing your energy costs.
Since new hot tub covers cost hundreds of dollars, most people are hesitant to replace them. With an average of 30-40% of the heat loss in a hot tub coming from its cover however, the inefficiency of old, worn out covers can cost much more in the space of only a few winter months. Knowing when to replace your hot tub cover can save you hundreds if not thousands of dollars in energy bills over the life of your hot tub.