After a wind storm, many a spa owner has found themselves wondering “where did my spa cover go?” If this happens to you and you are one of the lucky ones, you could find your spa cover or hot tub cover at least a quarter mile from your home. If not, you’ll have to look into buying a replacement that simply will not fly away next time.
Your spa or hot tub cover is likely to fly away because when wind comes at your spa, some of it will hit the side of the cabinet and have to go around. As air is pushed around the spa, some of it will be forced to go over. Once it breaks over the top of the rigid foam cover, it will set off a bit of ripple or swirl action which begins to suck upward on its rigid surface. This ripple or swirl action is what will eventually pull the spa cover up off the spa. The cover doesn’t need to move too much, because once a big enough gap is created, this will allow some air to get in underneath – which is all it takes to have your spa cover or hot tub cover flying away into the distance.
The good news is that spa supplies dealers are now offering spa covers and hot tub covers with various solutions that prevent these from flying away. For instance, it is possible to obtain spa covers and hot tub covers with heavy duty straps. Alternatively, you could go for a design that does not offer a rigid surface for the wind to lift on. This is a major improvement on the typical rigid foam spa covers that fly simply because they make a good wing.
You may also choose a spa cover design that does not resemble a wing, and which does not require straps or truck ratchets to secure it to your spa. Avoid spa covers or hot tub covers with a rigid foam board that rests across the top of the spa. Instead, go for one whose bottom will rest right on the water surface thereby removing most of the air gap beneath the cover. This will also remove the vacuum that builds up pressure which could cause the spa cover or hot tub cover to pop off. In order to resist lift and deflect the strongest winds, go for a dome shaped or soft spa cover, rather than a flat and rigid one.
Another tactic is to use a spa cover cap on top of your cover, to help keep the air out. However, if the wind is strong enough, it will first send your spa cap flying, and then your spa cover will take to the air. Heavy duty straps are key, for extra support use not just the straps attached to the spa cover, but use additional nylon webbing straps over top of the spa, from side to side.