Knife Edge Perimeter Overflow Pools - The Ultimate Perimeter Overflow Design

Internationally renown pool designer Paolo (Paul) Benedetti presents a new twist on the knife edge perimeter overflow pool - a 360 degree deck level vanishing edge! It might also be called a: no coping pool, zero edge pool, no edge pool, or edgeless pool. It is also known as the "Lautner Edge," named after the famous Los Angeles Architect, John Lautner, who conceived of the detail. However, my firm has refined the detail into a masonry knife edge!

These are not to be confused with horizon pools, gutter pools, waveless pools, grated overflow pools, perimeter overflow pools, slot overflow pools, flooded deck pools, slot edge pools, wet edge pools, vanishing edge, negative edge, infinity edge, disappearing edge pools,wetted edge, no edge, flooded coping pools, or wet deck pools, though they all provide essentially the same appearance... that the pool is overflowing.

The "knife edge" technique used on a perimeter overflow pool is the most complex of any of the edge techniques available. What makes this detail so unique, is that there is virtually no flooded coping or edge material... in essence, it is a "knife's edge." The water falls into a slot right at the top inside edge of the coping or decking material.

A Brilliant Mind

Los Angeles Architect John Lautner was one of the early pioneers of this technique. It first appeared on the Goldstein-Sheats residence in Beverly Hills. Though the detail was rudimentary, it is the inspiration for the watershapers of today.
The original detail utilized a
stainless steel gutter affixed to the concrete shell. The interior finish of the pool is bonded to the stainless steel.
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The inner wall of the stainless steel gutter mustn't flex or the pool's aggregate finish will delaminate. This necessitated the use of reinforcing ribs between the outer walls of the slot, which are visible from above. This detail also made the inside wall of the pool (at the slot) visibly thicker than that we use today.

One of the later watershapers to reintroduce the use of the Lautner Edge, was Brian VanBower of Miami, Florida. His knife edge detail also relies on the custom fabrication of a stainless steel gutter. Though my firm had previously used knife edges as a lesser detail on larger projects, we had always built them out of concrete & masonry. I have found that anytime you have to custom fabricate anything (especially stainless steel) it gets expensive FAST!

Refining the detail

The variations of the Lautner Edge that I have utilized have been both visible and hidden. I have utilized a raised exposed rim in order to create shallow layers of water or splash areas. I have utilized the "true" (though refined) Lautner Edge, in it's original concept - with the collection gutter hidden from view.

This design of mine from a few years ago, is an example of the utilization of both techniques on the same project. The elevated shallow area is created around the umbrella, by merely elevating the edge detail & allowing the water to spill over the top into a deck level slot.

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I later utilized a deck level version of this detail near some "floating steps" in the deep end of the pool. The use of various edge details on one pool, gives the viewer the illusion that the pool is "out of level." This use of forced perspective, tricks the eye into thinking that the pool is out of level. This is accomplished through the use of a regular tiled waterline and the use of a slot edge at the opposite end. A change in deck elevations allows for the mixed edge details, and facilitates the transition.
While this mixed use of edge details can be confusing, I added to the complexity of this project by adding 2 additional edge treatments... a standard vanishing edge (infinity edge) and a perimeter overflow spa.

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The spa has the illusion of spilling into the vanishing edge catch basin. But this is a definite no-no. For those who do not understand basic hydraulics - you need to go ask someone why!? A novice mistake for people who "talk the talk," but can't even "crawl the walk."


Evolution of an Idea

I saw some of the other international designers starting to design & build entire pools utilizing a custom fabricated stainless steel Lautner Edge. I saw this as an unnecessary waste of time, energy, and money. Problems arose when the dissimilar materials need to be "wed.' The interface between stainless steel & the concrete pool structure needed to be waterproof and absolutely solid. This oftentimes resulted in "overbuilding" of the stainless supports or gutter, in order to compensate for the unknowns.

I'd rather utilize what I know to has worked in the past, whenever possible. Why waste your energy and the added liability associated with inventing & building your own wheel?? Though we have been able to prove that we can bond glass & ceramic tile, granite and even plaster to stainless steel - why risk the chance when it can easily be avoided simply through the use of compatible materials?

I was called upon to design a pool for a local pool builder. Seems that he was under contract to build a conventional pool, when the landscape architect sold the property owner on the idea of a knife edge pool. He turned to me to resolve the design issues and to incorporate a concealed retractable pool cover into the floor of the spa (as unobtrusively as possible).

The finished product is gorgeous. It works with the site, as if the scene would be incomplete without it. This is what design is all about... it has to look as though it belongs!
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This is design perfection that John Lautner would be proud of!



Paolo Benedetti - Aquatic Artist
"Creating water as art."™
Aquatic Technology Pool & Spa
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