Next, consider the corners of the hot tub cover—are they square, radius (rounded), cut or another shape? These measurements must also be provided to the cover manufacturer, and depending on the cover’s corner style, the following will help simplify this task.
Measurements are not required for square corners; however, when dealing with radius corners, a carpenter’s square is required. Place the square on the outer corner of the hot tub’s acrylic lip and note the point where it begins to curve away. Measure the distance from this point to the inner corner of the square. Check the same distance on the opposite side, as these measurements should match. This distance is the radius measurement. If a carpenter’s square is not available, two straight edges can also be used.
Another way to measure radius corners is to trace them. Secure a sturdy piece of clear plastic or a sheet of paper over the entire corner with masking tape. Carefully trace the outer edge of the corner with a magic marker from beginning to end. This drawing can be faxed or mailed to the manufacturer.
If the radius corner measurements are incorrect, the cover may not seal properly and it may lose its visual appeal. (If the radius is within 25 mm (1 in.) or so, the cover will usually look fine). The larger the radius, the broader the curve. If a cover with a 304.8-mm (12-in.) radius corner is placed on a hot tub with a 152.4-mm (6-in.) radius corner the corner of the spa will stick out from under the cover, leaving a gap. The cover’s skirt will also be uselessly crushed underneath.
If the opposite occurs, with the spa having a larger radius than the cover, the corners of the cover will extend out over the lip of the hot tub, creating an improper seal and added opportunity for wind to catch it.
Cut corners also need to be measured. The length of the cut corner itself should be provided along with the measurements of the other sides of the cover. As always, remember to take care in providing the full length and width of the hot tub.
Although it may seem elementary, be sure to measure hot tubs with one cut corner from the topside to ensure the cut corner ends up in the right place. And, always draw the fold for hot tubs with one- and two-cut corners when ordering.
A common pitfall with four-cut-corner hot tubs is the distance between the cut corners is often provided instead of the full measurements. This results in a cover that is too small.
When dealing with an equal-sided octagon, all sides should be measured to make sure they are in fact equal—then only the diameter and side measurements need to be submitted.
Sometimes cut-corner hot tubs have radius corners, as well. These should be measured in the same manner as any larger radius corner. If in doubt, trace the radius. Since cut-corner hot tubs seem to be the most challenging to measure, a template can also be submitted.
No skirting around
The skirt is a flap of material that usually extends from the bottom of the cover to the bottom of the hot tub’s acrylic lip.
In some cases, a standard skirt length (approximately 63.5 mm [2.5 in.]) is included unless a specific measurement is included on the order form or indicated in the template database. If the hot tub cabinet has a protruding top rail, the cover may need to be ordered larger to allow the skirt to hang free. Another alternative is only measuring to the top of the rail so the skirt and rail just meet.
It should also be noted whether there are slits in the corners of the skirt or any area where the skirt length may differ. For example, spill-over hot tubs may have a flap on the skirt to cover the spill-over opening.
Cover strap measurements and locations are also important. Standard strap lengths are usually 203- to 228-mm (8- to 9-in.) long. If a different length is required and strap measurements are provided, be sure to indicate whether the measurement includes the length of the strap hardware. Also, if the straps need to be in a specific location, mark the drawing or template with an ‘X’ to indicate their position.
Finally, are there any cut-outs in the top of the cover? If so, a rough drawing should be provided detailing the cut-out’s length, width, depth and shape, along with its position on the cover. It should also indicate whether the foam, vinyl or both are being cut out.