A recessed-top guide automatic cover system is similar to the above in that the drive mechanism is also mounted below grade in a cover box. However, the location for the placement of the top-guide track is what sets this system apart. While the under-guide track is mounted beneath the coping, the top-guide track is located outside the pool perimeter.
There are two options for the installation of this system as well. A standard top-guide track can be mounted directly on top of the pool deck. It is a low-profile track approximately 13- to 15-mm (0.5- to 0.625-in.) thick and rounded on the edges to provide a clean look.
The second option is to use a recessed track. This track is mounted along the sides of the pool before the pool deck is poured, and positioned at the correct height so it will be flush with the top of the finished pool deck. Because this track system sits outside the pool perimeter, it is a great option when installing an automatic safety cover on a freeform pool.
When installing a recessed top-guide system, however, it is important to note the cover will operate under more stress as it is being pulled over the concrete deck. It takes little effort to move a cover across the water as in the case of an under-guide cover system, but when the cover is being pulled across the pool deck, it will have much more resistance. Therefore, to minimize this resistance, the amount of deck the cover will be pulled across should be less than 10 per cent of the cover’s total size. To help accomplish this, the cover tracks should be located within 76.2 to 102 mm (3 to 4 in.) from the pool’s edge when possible.
If the positioning of the guides is more than 10 per cent of the size of the cover, blowers can be installed to help the cover operate more smoothly. A blower will create a cushion of air for the cover to ride on, instead of dragging across the pool deck. The number of blowers, and their positioning, will depend on the cover size and the amount of pool deck it will be moved across.
Deck mount systems are made specifically for existing pools. In this case, both the drive mechanism and the standard top-guide cover track are mounted on the pool deck. This is the same standard top-guide track that can be used with recessed top-guide systems.
For deck mount installations, a bench can be built to cover the drive mechanism to protect it from the elements, while also providing seating for those enjoying the pool.
Very little renovation work is required when installing an automatic cover system on an existing pool. Essentially, electrical wiring will need to be run to the drive mechanism so a control switch can be mounted on the side of the bench. However, if a homeowner is willing to do more renovation, the pool deck can be saw-cut to allow a cover box to be installed below grade, moving the system from a deck-mount application to a recessed top-guide system.
When the drive mechanism is located below grade in a cover box, there are different lid options that can be used to enclose the cover box and provide protection for the drive mechanism. These can be as simple as a hinged aluminum lid that sits on top of the finished pool deck or a concrete walk-on lid that blends in with the rest of the pool coping.
When building a pool that will include an automatic cover, it is important to consider the following guidelines:
Drainage from the cover box
If the drive mechanism is located below grade in a cover box, it is important to have adequate drainage from the box. The most frequent cause of automatic cover system failure is lack of sufficient drainage. When a cover box is flooded, not only does the motor sit submerged in water, but the roll up tube can also fill with water, which can weigh several hundred pounds. This can lead to damage of the roll up tube and/or the cover fabric.
Control switch location
The location of the control switch is critical to ensure the cover system operates correctly. It must be located in a position where the entire pool is within view so the person operating the cover can watch as it opens and/or closes. If a problem arises, the operator can immediately release the control switch, preventing damage to the cover, and then investigate the problem.
The ideal placement of the control switch is along the length of the pool, but closer to the end where the drive mechanism is located. This will provide the operator with a good view as the cover completely opens and/or closes.
Drop to water
Drop to water refers to the distance from the cover track to the water level in the pool. It is important to keep the track positioned as close to the water as possible. For an under guide cover system, the tracks are generally positioned 76 to 102 mm (3 to 4 in.) above the water. For recessed top-guide or deck-mount systems, the tracks are generally located 127 to 152 mm (5 to 6 in.) above the water.