Feature Article - May/June 2006
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Undercover Operations

With proper planning, adding a pool enclosure can boost patronage and profits

By Dawn Klingensmith

Know the Code

Prefabricated see-through pool enclosures can be assembled in a matter of days, and when the last panel is in place, occupants ideally don't sense the presence of the structure and feel seamlessly connected to the great outdoors. But make no mistake: These are permanent structures, and just like their brick-and-mortar brethren, they are subject to strict building codes.

The Lompoc Aquatic Center in Lompoc, Calif., is one of the largest enclosures of this type ever built, and in part because of its size, architect Jim Moore had to clear three daunting California Building Code (CBC) hurdles.

  • Per CBC Chapter 31 B, occupant load calculations are based on a ratio involving the surface area of the pool. Using this method, Moore arrived at 775 occupants, a number that normally would require an A2.1 assembly area occupancy classification, which entails fire rating the structural frame. The manufacturer's aluminum frame system did not lend itself to this type of treatment. Using an exception spelled out in CBC code (1003.2.2.2), Moore prepared and gained approval of an occupant load management plan and added exit doors to his design. By doing so, he attained an A-3 occupancy classification for the enclosure, which does not require a fire-rated structural frame.
  • The enclosure's double-layer polycarbonate roof panels have a Class C fire safety rating, but based on occupancy class, a Class B roof rating is required. Satisfying this requirement meant limiting the use of polycarbonate to no more than 33 percent of the roof area. Working with Moore, the manufacturer designed a three-component roof system, using the standard polycarbonate for the operable roof sections, which took up the allowable 33 percent, and fixed insulated glass and metal panels in all other areas. All materials were specified in a blue color to maintain the aesthetic harmony of the roof.
  • Due to the large size of the enclosure, CBC Section 505.3 required that a full sprinkler system be installed. However, the building department ultimately ruled that areas directly below the operable roof did not need sprinklers because the retractable portions of the roof are situated directly over pool areas. Moreover, installing sprinkler heads in the operable roof area belied common sense because whenever the roof was open they would lack the heat bank necessary to activate them in case of a fire.