An under track system has to go in while the pool is being built. If your pool is already finished, or it’s a kidney, lagoon, or other freeform shape, an automatic pool cover for existing pools almost always means top track. The tracks mount on top of the deck instead of under the coping, so there’s no need to tear off what you already have.
There’s one catch every homeowner should understand before choosing one: your pool can be any shape, but the cover is always a rectangle.
How an Automatic Pool Cover for Existing Pools Works
Top track, recessed horizontal track (RHT), and screw-down RHT are the systems used to cover existing pools, freeform pools, and rectangles with freeform features like outside benches or walk-out steps. A track runs along each side of the cover area, and the cover is pulled across the deck and the water between them.
Instead of a slider tucked under the coping, these systems use a wheel assembly that carries the leading edge bar above the deck. That puts the bar almost 7 inches above the deck surface. It also means the tracks sit where they collect deck debris, so they need regular cleaning. In leafy parts of New Jersey and Pennsylvania, plan on clearing them often during fall.
Your Pool Is Freeform. The Cover Isn’t.
Because the cover is rectangular, it has to be big enough to reach every edge of the pool. Any part of that rectangle that isn’t over water is over deck.
That creates three effects:
- A bigger cover. Some shapes need a very large rectangle to fully cover the pool.
- More cost. Increasing the size, especially pushing the width past 24 feet, raises the price of the cover.
- More deck needed. The deck has to extend far enough around the pool to hold the tracks and the full cover area.
What Is Deck Drag?
Deck drag is the part of the cover that slides across the deck instead of floating on the water. On the water, an automatic cover glides. On concrete or stone, it drags. The more of your rectangle that sits over deck, the more deck drag you have. When a large area of deck has to be covered, Coverstar’s guidance is to keep the pool shape within a 20′ x 44′ rectangle.
Coverstar’s planning guide gives two examples:
| Good Fit | Poor Fit | |
|---|---|---|
| Cover size | 16′ x 42’6″ | 29′ x 48’6″ |
| Covered area | 680 sq ft | 1,406 sq ft |
| Share that is deck | 23% | 48% |
| Deck drag | 156 sq ft | 670 sq ft |
The good-fit pool is long and narrow, so it fills most of its rectangle. The poor-fit pool has deep curves that leave nearly half the cover dragging over deck, with more than four times the deck drag.
How to Keep Deck Drag Down
- Keep the pool shape as close to rectangular as the design allows.
- Keep the cover box close to the pool. Extra deck between the housing and the water is extra drag.
- Stay within the 20′ x 44′ guideline when a lot of deck will be covered.
- Avoid pushing the cover width past 24 feet unless the design really needs it.
Choosing a Top Track System for an Existing Pool
Once the rectangle is sized, the next decisions are which track to use and where the mechanism lives.
Track Style
Standard top track sits on the deck. Recessed horizontal track and the vertical slim flush track sit lower in the deck for a cleaner look. We break down all four styles in our guide to top track pool cover options.
Mechanism Location
A recessed mechanism sits below the deck under a lid. A deck mount mechanism sits on top of the deck, which makes it an economical choice for existing pools. It can be left open, covered with end housings, or hidden inside a bench. See our post on deck mounted automatic pool covers and bench housings.
Your Deck Material
None of these tracks can be installed on dry-laid pavers. They need a concrete deck or deck stone that’s cemented in place. If your patio is dry-laid, that has to be addressed before a top track cover can go in. Dry-laid patios are common on older pools in the region, so check early.
Retrofit or Rebuild?
Top track is designed specifically for pools that are already in the ground. You keep your existing coping, and the installation work happens on the deck. The tradeoffs are a leading edge bar that rides higher than under track and tracks that need more cleaning. For most owners, that’s a fair trade for an automatic pool cover for existing pools that doesn’t require rebuilding the pool edge.
If you’re building new and want a freeform look with under track’s lower profile, a pool-in-pool design is worth comparing.
Frequently Asked Questions
Can you put an automatic cover on an existing pool?
Yes. Top track, recessed horizontal track, and screw-down RHT systems are all designed to cover existing pools. The tracks mount on the deck, so the coping doesn’t need to be rebuilt.
Can an automatic cover fit a freeform or kidney-shaped pool?
Yes, but the cover itself is always rectangular. It has to cover the full pool, so any curved areas leave sections of cover resting on the deck.
What is deck drag on a pool cover?
Deck drag is the area of the cover that slides across the deck instead of floating on the water. Pool shapes that don’t fill their rectangle create more deck drag.
Does a wider pool cover cost more?
Yes. Increasing the cover size raises the cost, and the jump is most noticeable once the width goes past 24 feet.
Can top track be installed on pavers?
Not on dry-laid pavers. The tracks need a concrete deck or deck stone that’s cemented in place.
