Wall height and design
One of the most common mistakes builders make is to construct the beam wall, separating the cover trough from the pool, much higher than the vanishing edge wall. The infinity edge wall must be roughly 12.7 to 25.4 mm (0.5 to 1 in.) lower than the separation beam wall. Since the tracks on either side of the pool are not perfectly parallel in this case, the auto cover must be modified using gliders to compensate for the height difference between the two tracks. Gliders are added to ensure the cover operates smoothly.
One of the most important parts of this pool design is the vanishing edge wall, which drops into the catch basin. These walls are generally designed as 90-degree vertical structures. In some cases, designers may create a 45-degree angle, so the water falls off more slowly and quietly than at a 90-degree angle. However, one of the drawbacks of a 45-degree angle is the track is not completely hidden as it is on a 90-degree wall. In the latter, the track remains concealed unless one is looking up from behind the wall.
There are many ways to build a vanishing edge pool, and certain methods of construction work better than others when installing an auto cover. For example, the slope of the wall that flows into the catch basin can either be sloped toward the pool or away from it.
“In our experience, the walls that slope in or toward the water hide the track better compared to when the wall is sloping out or away from the pool,” says Moss.
Water levels and water displacement
Another factor to consider in all infinity pools is water displacement, which is critical to the installation and proper functionality of an auto cover.
“Hydraulics is key to vanishing edge pools,” says Moss. “The water that goes into the drain must be pumped back into circulation immediately to keep the hydraulics of the pool working.”
This is especially important as a lot of water is displaced with bather activity as well as the opening and closing of the cover. The water has to go ‘somewhere’ when the cover rolls up or retracts. As a result, it is pushed into the catch basin at the bottom of the vanishing edge as well as into the vault area where the cover rolls into when it is opened.
“To accommodate this, we ensure the drains from the automatic cover trough drain into the catch basin to capture the water that is displaced, so this water will not go to waste,” explains Horwood. “It’s an extra plumbing step, but is crucial to ensure we do not lose too much water.”
The containment basin must be large enough to catch all of the water or the auto-fill feature will keep kicking in to raise the level back up. Homeowners must keep in mind the auto cover cannot be closed immediately after a lot of activity in the pool as the water level will be too low (because of displaced and lost water) for the cover to move across the top of the pool. The design of the cover requires it to be ‘held up’ by the pool water; hence, the customer may need to wait 20 to 30 minutes to put it back on. During this time, the water returns to the pool after being pushed into the catch basin. Note: Auto covers travel well over pool water and along wet walls; they do not complement dry walls.
