It’s a confident builder who doesn’t get a bit nervous when faced with a perimeter-overflow pool. Even high-level concrete builders who’ve tackled several vanishing-edge projects will recount being a little intimidated at the precision required.

But when a customer wanted the benefits of one-piece fiberglass along with the beauty of perimeter-overflow, it didn’t occur to Marshall Knight to worry — even though he had never heard of such a pool being built.

“There was no reason why I couldn’t do it,” says the owner/operator of Bahamas Pool & Patio Ltd. in Nassau, New Providence, Bahamas. “The only difference between my pool and a regular pool is the gutter system itself. I know that there’s a logical way to figure this stuff out.”

Like the two other fiberglass-pool mavericks discussed here, Knight was aware that there would be some concerns specific to building a perimeter overflow using a one-piece fiberglass vessel.

There are three basic challenges to this type of installation: Leveling the edge, crafting the gutter, and preventing leaks.

  • Leveling the edge: The perimeter of any four-sided vanishing edge must be as close to level as possible — most concrete builders try to work within 1/16- to 1/32-inch tolerances.
  • With concrete, if the initial shooting isn’t absolutely precise, the crew can grind and float the top until everything falls within the desired tolerance. But fiberglass doesn’t offer that luxury. A gigantic shell must be leveled, and every little nudge on one area will tweak another part of the pool out of alignment.

  • Crafting the gutter: For concrete builders, shooting or pouring the gutters is just a more advanced version of what they already do. Additionally, this component is built as part of the overall shell. But fiberglass installers must find a way to attach a gutter system to the shell.
  • Preventing leaks: With the shell and gutter systems being separate entities, the builders need to prevent water from leaking as it transitions out of the pool.


• On the Edge

Expert advice on creating the perimeter-overflow effect on concrete pools.