Replacing Hot Tub Covers

When is it time to replace a hot tub cover?

While there is no set point at which a cover should be replaced, most covers will need to be replaced after 5-7 years. Over time, hot tub covers will become saturated with water, becoming heavier and heavier. Eventually they will either become too heavy to lift or the seam between the two sides of the cover will tear and the cover will split in two. Covers can also start to "cup" if they are subjected to  heavy loads, like an excessive amount of snow or ice.

Covers should be replaced as soon as you notice either happen. Foam insulates by trapping

A badly cupped hot tub cover. Any cover
that develops puddles like this is cupped and
should be replaced.

warm air in the bubbles of the foam. As  covers become saturated and those bubbles fill with water the cover will lose it's ability to effectively insulate and can cause your monthly energy bill to increase. A cupped hot tub cover will also cause an increase in energy costs as it causes the corners of the cover to lift up, breaking the seal around the edge and allowing the heat to escape.

What to look for when buying a new cover

The first thing to do when looking for a new hot tub cover is to look at a sample of the covers the retailer provides (or at least a sample of the vinyl). Check the thickness of the vinyl, the thickness of the cover, and the quality of the stitching as these are usually the first things that are neglected on cheaper covers.

 If your hot tub has a cover lifter we've found that a 4"-3" tapered cover tends to sit best, and last the longest. Thicker covers will tend to put added stress on the seam of the cover when sitting on the arm of the cover lifter. As it gets saturated (and heavier) it will rip on that seam. The added insulating ability of the thicker cover is therefore negated by having to buy a new cover sooner.

Most retailers will also offer different "foam densities". The higher the density of the foam, the better the insulating value of the foam, and the stronger the cover will be. While the added insulating value of higher foam densities is not very significant, the added strength can be a big plus if you experience heavy snowfalls, or if there is a chance of pets or children climbing on the cover (still not recommended).

Some common extras you can get for covers are a full foam sealer (also known as a full hinge seal or centre seal), aluminum backing for the foam to help strengthen the centre of the cover (and help prevent cupping under heavy loads), and a vapour barrier wrap around the foam.

Thermal images of a cover with and
without a full foam sealer. Without the
full foam sealer there  is a 19 degree
difference, with it less than 1 degree!

 A full foam sealer is a piece of foam that fills and insulates the area between the two sides of the cover. Without it the cover will have a 1" gap that is only insulated by the cover's vinyl skin when it is closed. Most covers will come standard with only small (4") pieces of foam on either end of the cover. These are useful for preventing evaporation, but do not offer much in the way of insulation.

Wrapping the foam with a plastic vapour barrier will help slow down the rate at which water saturates the foam, extending the life of the cover. They will typically range in thickness from 2ml to 10ml, the thicker the better.

Lastly, watch out for some online retailers that will advertise low prices for their basic covers. When those retailer's covers are priced with features that are comparable to what other retailers provide as standard they will often end up being very similar priced. By buying a cover online you may also be losing out on free delivery or disposal of your old cover, and if there is a problem with the cover you would have to worry about return shipping and dealing with notoriously bad online service.

Extending the life of your hot tub cover

We'll close out this entry with a few tips for how to extend the life of your current hot tub cover.

•  Keep the cover clipped in to prevent it being potentially carried off and damaged by high winds.
•  Avoid resting anything heavy on your cover, remove any heavy loads of snow or ice in the winter. When removing snow off of a cover don't use a shovel. Shovel blades can catch on the cover and tear the vinyl, leading to the cover rapidly becoming waterlogged. Brushes used for cars work well.
• Leave your cover fully open for at least 30 minutes after shocking your hot tub. After you shock the hot tub, strong chemical vapours are released that can harm the underside of the cover.
•  If you don't have a cover lifter, use the cover's handles when moving the cover on and off the hot tub. This will reduce wear on the stitched seams of the cover and prevent them tearing from improper handling.
• Clean your cover using a UV protecting spray at least twice a year to help reduce the harmful effects of the sun on the vinyl finish and stitching.