Should I get a flat cover for a spa in a protected gazebo?

My hot tub is enclosed by a gazebo. I have heard of flat covers for indoor hot tubs. Would a flat hot tub cover be best for my set up?

David in Pikesville, Maryland

Thank you for asking The Pros David!

You are definitely on the right track with your thinking. Most covers are made with a slope so the rain will run off and not puddle on top of the cover. As with every thing in life, choices are a matter of compromise. A six inch thick cover that tapers to four inches thick at the edges has the effective average thickness of 5 inches. The R-value would be calculated exactly as if it were a five inch thick flat cover.

The difference is the five inch thick and flat cover does not have ANY four inch thick areas that would hasten heat loss, so the five inch thick flat cover will insulate better. This is like the example of a chain only being as strong as its weakest link.

The other difference is the strength of the cover’s internal foam cores. Again, the five inch thick and flat cover will have no areas only four inches thick, resulting in a stronger cover overall as well.

This picture shows a flat cover. It does appear that it is not protected from the weather by any type of enclosure. So why would it be flat? Chances are this is a flat Walk On cover, since the spa is installed in the deck and it will be stepped on and even walked on.

As you live in Maryland, The Pros suspect you see your share of cold weather. If you keep your spa hot continuously through the winter, then upgrading to a flat cover will certainly pay for itself over a single winter. The Pros recommend also upgrading your selection with the extra foam across the hinge – the long steam stopper or continuous hinge seal – to complete your full insulation of the hot tub. This picture shows this extra foam hanging down across the fold.

Happy Tubbing!

Ethel Elliott