It might be hard to tell when your hot tub cover is failing. It could be becoming waterlogged slowly over time, in which case you might not notice the extra weight. Likewise, your power bills could be creeping up for no apparent reason.
Because it’s so hard to tell, it’s worth your time to perform an annual or semi-annual inspection of your hot tub cover.
The inspection is simple enough. Take the time to go over every inch of your hot tub cover with a flashlight and look for any cracks or tears.
These cracks and tears allow moisture and steam to get into the insulating foam which is very, very bad. Water in foam insulation cancels out any insulating properties it might have had, driving up your energy bills. Worse, it creates a breeding ground for bacteria that can drip down into your tub.
There are many adhesives and patch kits for fixing a hot tub cover. A word of warning, though: if you only discovered a tear when doing an inspection, the damage is likely already done. Patch kits are only effective when used right away: as soon as the cover is dropped or torn, for example.
If a tear has been open for months, odds are that the insulation inside is already a useless spongy paste.
Similarly, if you did patch a tear when it opened, and on inspection you find that the patch has failed, your cover has been compromised.
Replacing the Cover
Covers are expendable. They get used up and need to be replaced. That said, they do not need to be quite so expendable as the shoddy covers that typically are provided by spa dealerships.
A good high-quality cover, with strong material and stitching should last for several years without any tears appearing. Spending more on a good cover now saves you from throwing out and buying several cheap covers in the future.