If you have a hot tub, you most likely already have a hot tub cover - the cover that came with it. The question is, is that hot tub cover the best cover for you hot tub? Hot tub covers serve four major purposes. One, they keep impurities out of your water. Two, they are also important in terms of safety - pets or small children could fall into a hot tub without a cover. Three, hot tub covers help hot tubs retain heat, keeping heating bills low. Four, they protect hot tub shells from direct sun exposure, which can harm hot tubs.
So, how do you determine whether or not your hot tub cover is working for you? If you have children or pets, you definitely want to keep your cover on when you are not using the hot tub. Make sure that your hot tub cover fits securely over your hot tub - also make sure that your cover is the right size - and that it is sturdy and durable. In fact, having a hot tub cover that fits securely also helps keep impurities out of your water while keeping heat in.
Over time, your hot tub cover may become heavy and waterlogged, maybe even moldy. When this happens, your cover cannot insulate as well. In this case, it may be time to get a new hot tub cover, or at least a floating foam blanket. You can help prevent water-logging by unzipping your hot tub cover every 2 to 3 months and allowing the foam to dry out. Also realize that a hot tub cover can also become worn and creased where it has been folded open many times. A crease in your hot tub cover may allow more heat to escape than would be able to otherwise.
Most hot tub covers are all insulated with the same material: Expanded Polystyrene (EPS). So, it is not the material that matters when it comes to insulation, but the thickness. The thicker, the better. Hot tub covers have an R-value. The R-value refers to a material's ability to resist the flow of heat. The R-value is based on thickness. In general, the higher the R-value, the better.
Hot tub covers can be very heavy, even when they are not waterlogged. This is good, because it makes it that much harder for a child to find his or her way into a hot tub unsupervised, but it can make it hard to open up your hot tub. If your hot tub cover is too heavy, you may want to consider getting a cover lifter. A cover lifter makes the huge ordeal of lifting off the hot tub cover much less of an ordeal.
Be aware that outdoor hot tub covers may wear more quickly than indoor ones, because they are exposed to the elements. All in all, a hot tub cover will not last as long as your hot tub, but it is up to you to decide when and how to replace it. In the long run, buying a new cover may be better than risking high heating bills.