Rolling Rocks – Cutting Edge

CUTTING EDGE POOL DESIGN: A Guide to Swimming Pool Edge Types

One of the hottest current design trends in the pool industry is to create a Knife-Edge Perimeter. Or is that a Zero-Edge Perimeter? Maybe it’s a Negative Edge or Infinity Edge? What is a Lautner Edge? Where does a Perimeter Overflow fit in? Not only are there several swimming pool edge types, each type can be referred to by several different names. This often causes confusion among clients when approaching the design of their new pool. It’s important to have a clear understanding of these different edge types in order to choose the one that will be most suitable for your project. Here, we clear up the confusion over Pool Edge Types and offer some key points to consider when meeting with your designer.

NEGATIVE EDGE

Image 1: 17th Century Negative Edge, Stag Fountain, Palace of Versailles, France

Negative Edge pools are known in the industry by several different names; Infinity Edge, Disappearing Edge, Vanishing Edge and Knife Edge. Recently the term ‘Knife Edge’ has been used when referring to Lautner Edges (more on Lautner Edges below) due to the similarity in structural design. But traditionally when a client requests a Knife Edge it is a negative edge that they have in mind. In fact, the term Knife Edge actually refers to a design component of negative edge, flooded coping and lautner edge systems. It is the actual point at which water spills over the edge of the pool. In a negative edge design the water spills over the knife edge, is captured in either a basin or another pool at a lower elevation, then recirculated back to the upper pool.

One of the first Negative Edge designs ever be put into practice is featured on the Stag Fountain at the famous Palace of Versailles in France. Built in the 17^th century, the Stag Fountain was considered a technological marvel of its time. The fountain’s negative edge faces out and the viewer can see the water spilling over into the basin.

Negative Edge Pools are ideal for clients with hillside or sloped lots. A Negative Edge gives the viewer the impression that the water has no boundary (see Image 1). In fact the term ‘Disappearing or Vanishing Edge’ is a perfect description as the pool edge seems to disappear or vanish into the horizon. The knife edge can be either angled in or out depending upon the design needs and desired effects (see Images 2 & 3).

 

Image 2: Negative Edge View from Pool, show the “disappearing effect.”

 

Image 3: Knife Edge with Custom Stone Detail

Image 4: Reverse Knife Edge with Hidden Basin

Image 5: Raised Perimeter Overflow Spa

PERIMETER OVERFLOW

There are three types of Perimeter Overflow Edges, sometimes called Zero-Edge Perimeter; Raised Overflow Perimeter, Lautner Edge and Flooded Coping Perimeter, often confused with a Lautner Edge even by some industry professionals. (more on Lautner Edges Below). With a Raised Perimeter Overflow, the entire body of water is elevated above deck level so that water can spill over all sides (see Image 4). Flooded Coping Perimeters are often confused with Lautner Edges for two big reasons; first, the finished products look similar essentially creating a sheet of water flush with the level of the deck, and secondly because the hydraulic function is similar. The main difference between these edge types is visual. With a Flooded Coping Perimeter you can see the bond beam vs. a true Lautner Edge where the bond beam is completely hidden from view (compare images 5&6).

Raised Perimeter Overflow Perimeters are great for clients with flat yards looking to add some interest to the pool area. One of the most common requests is to raise just the spa alongside the pool, although the entire pool itself can be raised as well. This edge type works well not just on geometric shapes like squares and rectangles but also round and freeform shapes. As long as one section of the raised area is not higher than any other nearly any shape can be used and still produce the same visual effect.

Image 6: Flooded Coping Edge, notice the exposed, finished bond beam at pool’s edge. Photo Credit: Questar Pools, Escondido, CA

Image 7: A Lautner Edge Swimming Pool, Sheats-Goldstein Residence, Los Angeles, CA

LAUTNER EDGE

A Lautner Edge is a very specific type of Perimeter Overflow Edge, sometimes referred to as a Knife Edge or Deck-Level Perimeter Overflow and most often confused with Flooded Coping Perimeter Edges. It gets its name from the architect who invented the system, John Lautner. From 1933 to 1939 John apprenticed under world renowned architect Frank Lloyd Wright. Wright’s influence can be seen in many of his designs. A beautiful example of this Lautner Edge System can be seen at the Sheats-Goldstein Residence in Los Angeles, California.

As with Flooded Coping Perimeters, the water in a Lautner Edge Pool appears to float at deck level.   When a swimmer walks to the edge of the pool and looks down they are seeing the full depth of the pool at that particular point as opposed to Flooded Coping Perimeters where you would instead be looking at the submerged finished bond beam. (compare images 4&5).

Lautner Swimming Pool Edges provide the “sleekest” appearance of all the edge types we’ve discussed today. They are also the most complex type of edge and as such are consequently the most expensive. Due to the complexity of design and precision necessary throughout the construction process it is extremely important that the client does their research and chooses a pool builder with the experience to get the job done right the first time.

Image 8: Lautner Edge, notice the water is level with the surrounding artificial turf and there is no transition material such as coping. Also notice the Raised Perimeter Overflow rectangular feature.

COMBINATION EDGES

Pool Edge Types do not have to be used exclusive of one another. Many clients choose to combine more than one type, adding visual interest to the pool. Image 6 shows a combination of edge types; the rectangular feature in the center of the water feature is a Raised Perimeter Overflow while the round feature ends in a custom turf edge utilizing the Lautner system. A qualified pool designer can help a client choose the proper edge type(s) that will work well with their property and fulfill the client’s vision.

Contact Us today to discuss the design of your future backyard swimming pool.