|Measuring Your Square Spa Cover or
measure just the spa (acrylic), or should I include the wood rim?
is a personal preference, however most folks measure just the spa acrylic,
lip to lip. (See figure below). In some cases you may want to measure to the
wood rim, only because it may look better to you and it doesn't create a
"rim" for leaves and other items to collect on. It does not help one way or
another with energy efficiency.
Another thing to consider is the cover skirt/flap, you will want this to
hang STRAIGHT DOWN. So, if the lip of the spa is at an angle, make sure you
measure the cover long enough to achieve this. You don't want the skirt
sticking out by measuring your cover too short. Also, measure the skirt (3"
enough to cover the spa lip, or the spa cabinet rim. (See figure below)
always better to make the cover size a little bit bigger than your spa when
measuring. If you make a mistake, and measure too small, the cover will not
fit properly, will not sit flat and will not hold the heat in.