Inground Vinyl Pools: Infinity or Negative Edge

An infinity edge pool, also called a vanishing edge or negative edge pool, was pioneered by Lew Akins and Skip Phillips who began building them for clients in the late 80's. The first vinyl liner infinity edge pool is credited to Tommy Johnson, a vinyl pool builder who has been installing them for 20 years in Alabama.

Infinity edge pools are used to accentuate the view beyond the pool. Without an edge on the far side of the pool, the pool does not obstruct the view, but blends with the horizon. Traditionally used on pools that overlook oceans or large lakes, to blend the two bodies of water, it also works very well with mountain or valley views.

Building a Vinyl Infinity Edge Pool

After the spillway wall is built, the vinyl pool wall panels are connected to the wall, for both the pool, and for the catch basin mounted below the spillway. Most catch basins are a few feet longer than the spillway, 12-24" wide and up to 42" deep, depending on the size of the pool. The larger the pool is, the larger the catch basin needs to be.

High winds and powerful rains can cause a lot of splashing of pool water around the catch basin. Account for this when sizing the catch basin, and when landscaping around the outside of the catch basin.


To build a vinyl pool with a negative edge, the first steps is to pour a foundation of concrete - 18" wide x 18" deep x the length of your negative edge. Then, on top of the foundation, construct a steel reinforced wall of concrete, with 42" above grade, and 18" below grade. Coat the wall with several layers of waterproofing, and then coat with pool plaster mix. Finish the wall with tile, stone or marble.

  • Construct a concrete wall to serve as the spillway, and one wall of the catch basin.
  • The wall must be waterproofed on all sides,
  • Vinyl wall panels connect to the spillway wall inside the pool, and on 3 sides of the catch basin.
  • Laser levels or transits are used to build the 12' thick concrete spillway wall at a precise height.


The liner is affixed to the top of the spillway wall, to a special track that is gasketed in place. The top of the spillway wall is covered in tile, stone or marble which is continued into the interior of the catch basin. Inside the catch basin is a dual drain suction manifold, that feeds water to the booster pump, which then pumps it back into the pool.

  • Spillway, or weir typically slopes away from the pool. The liner is gasketed to the top of the finished wall.
  • Slope of the spillway and the outside, or back wall of the catch basin, is faced with tile, stone or marble.
  • The catch basin should be deep enough to handle 1-2" of overflow from many swimmers or heavy rains.


A negative edge pool overflows whenever the pump is running. When the booster pump is not running, the water level will slowly drain into the catch basin and the pool level will drop to just below the lip or edge. Infinity pools run the secondary pump several times per day for short periods, to filter the catch basin water, and help skim the pool surface. The catch basin is never empty, or else the booster pump would lose prime, it sits constantly 1/3 - 2/3 full, with the water is recycled into the pool daily.

  • A secondary, dedicated pump is connected to the pool via a deep end, dual drain suction manifold.
  • Check valves and a Hartford Loop is plumbed to prevent pool draining into basin when pump shuts off.
  • Pump size is determined by the wall size and pipe size; with about 5 gpm for every foot of spillway.


  • Auto-Fill device is used, to keep the pool water level above the spillway.
  • Auto-Drain device (hole in skimmer), is used to remove excess rain water from pool.
  • Return jets are plumbed into deep end wall or floor, dual main drains used in catch basin.

Vinyl Perimeter Edge Pools

If you think the calculations and finish measurements are critical for an infinity pool, try creating a "Zero Edge" pool, one that spills over all four sides of the pool! This requires that the height of all four walls be within 1/8" of each other, all the way around, and a pump powerful enough to create consistent and continuous flow all the way around the pool perimeter.

You may have seen this type of design used on fountains or memorials. It can also be used for pools, when the pool is intended to be a reflecting pool, or just ultra modern. However, this type of pool construction is beyond many DIY pool builders. And, it's beyond the scope of our DIY pool kits, as this should be built with a concrete wall all the way around.

Is an Infinity Edge Vinyl Pool Possible?

Yes, it is possible and has been done hundreds of times - but I want to stress again that building a vinyl pool with a negative edge is not kids stuff - it takes some real engineering to pull off well, and it may not be suitable for all locations or conditions.

But if you're up for a challenge - I'd recommend some more study of vinyl liner infinity edge pool construction, and when you're ready to build your own pool - call ITS - the vinyl inground pool kit experts, who will help you plan and build your own inground pool with a vanishing edge!

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