What is a spa cover made of?
Most manufacturers use basically the same materials to make their covers. Styrofoam on the inside, covered with marine grade vinyl on the outside. But there’s a lot more to it than that. The vinyl is treated to resist the damaging effects of ultra violet sunrays. The styrofoam inserts are reinforced with aluminum to make them stronger, they are typically tapered to be thicker in the center, and they are sealed in plastic to keep out moisture. Here’s something many people don’t know, even some retailers who sell spa covers. Foam inserts come in several densities. The density refers to how tightly the foam is packed, and thus how rigid it is. If you don’t ask, then most manufacturers will make the cover with one pound density foam. This means that if you had a cubic foot of this foam, it would weigh one pound. But foam also comes in one and a half pound density, and some manufacturers offer a two pound density. They will typically charge $15 to $25 more for denser foam, but it’s worth it
