To operate your hot tub or spa safely and efficiently, keep it covered. There are three cover types: floating thermal insulator, Styrofoam hard spa covers, and structural. Floating thermal insulators float on the water’s surface. There are two types, bubble blanket and micro cell floating blanket. Both are lightweight, inexpensive, and stop surface evaporation, a major source of heat loss. You can use them indoors year round or outdoors during the summer. Neither type prevents people or animals from falling into the water. Styrofoam hard spa covers are made from three-inch Styrofoam wrapped in Naugahyde or vinyl. They are popular despite these disadvantages: They become waterlogged easily. A waterlogged cover is difficult for one person to lift and has substantially reduced R-value. These covers break so easily, children have fallen through them and drowned. Life expectancy is only one to three years, heat loss associated is monumental. Structural covers are constructed from solid wood, or a other strong material. Be wary of plastic covers because they warp in the sunlight. Solid wood covers are strong, but heavy, awkward, and bulky. Another type of structural cover is the rolling cover. Great Northern’s Roll-Up® Covers are made from solid wood slats bonded to insulating, flexible backing. The are strong, compact, and easy to use. You don’t have to lift them, just roll them up. Roll-Up® Covers retain their R-value because they don’t waterlog. These covers keep children, pets, dirt and debris out of the tub while the keep heat and moisture in. If you have a particularly inquisitive child, you can secure the Roll-Up® Cover with a hasp and lock. And only the Great Northern® Roll-Up® Cover features a Ten Year Limited "won't waterlog" Warranty - longest in the industry!