Electrical and lighting
Early collaboration between the electrical contractor and pool designer will ensure the proper equipment is specified, such as pool pumps, heaters, and whirlpool jets. These specifications should not only address pool health regulations and general code requirements, but also include considerations about energy efficiency and maintenance. Energy-efficient equipment may help offset the owner’s costs and minimize maintenance scheduling in the long term.
Bonding
While proper specifications and electrical connections are important, electrical safety should not be overlooked. The pool contractor and electrician should be well-versed in electrical bonding and grounding. All metallic components associated with the pool structure should maintain equal resistance. For instance, ladders must be electrically interconnected and grounded to the earth.
Additionally, structural and pool engineers should ensure steel reinforcement is bonded. Typically, electrical and metallic components of the pool are joined with a wire to form a non-resistive path between them. This is to prevent an electrical potential from existing. The goal of bonding is to connect, contain, and prevent the transmission of electrical voltage that would endanger a life or damage pool equipment. Bonding should not be an afterthought.
Grounding
The goal of grounding is to ensure the bonded components redirect harmful excess electrical current to the ground. The pool’s electrical network and panel must be grounded to dissipate excess electricity. Without a proper grounding system, people or pool equipment could become the conductor. Without both bonding and grounding, the risk is too high and repairs will be costly and timely.
Lighting
Ambient lighting specifications and layouts tend toward the vision of the designer. However, certain building codes and local municipalities have governances to protect wildlife. If the client wants lighting for night swimming, certain requirements need to be met, including those imposed by the health department. Early and frequent co-ordination will help promote safety and performance, while maintaining esthetics.
Exposed concrete within a garage
It may not exist in all configurations, but the underbelly of a rooftop pool may occupy a garage structure below.
Cars exhaust various toxic and non-toxic gases. Governing bodies within the mechanical building code, or industry standards such as those set by the National Energy Code of Canada for Buildings (NECB), have mandated venting requirements that address the carbon monoxide emitted from vehicles.
However, the carbon dioxide exhausted by vehicles idling or travelling within the garage can react with freshly placed concrete to produce a soft chalk residue on the surface, through a chemical reaction known as carbonation. Carbonation of reinforced concrete is a form of deterioration and contributes to the corrosion of reinforcement.
Other contributors to the corrosion of embedded steel are oxygen from the atmosphere and moisture from humidity or leaks from the pool above. Depending on the conditions, exposed and unprotected concrete may require an anti-carbonation coating to protect against the ingress of harmful elements, while still allowing the concrete to breathe.
Conclusion
Early co-ordination between design professionals and the construction team is necessary. During co-ordination and design, certain preventative measures should be taken to extend the life of the pool, maintain its structural integrity, avoid imminent danger to personnel, prevent damage to the property below, and hinder unnecessary future repairs. The pool system is complex, but attention to detail, specifications, and the interaction between trades can yield a safe, functional, and beautiful rooftop amenity pool.
Patrick St. Louis, LEED GA, is a project director with Thornton Tomasetti, Inc. (TT) in the Fort Lauderdale, Fla., office. Mr. St. Louis has been with TT for over eight years with a primary focus on forensic architecture. He has a bachelor’s degree from Florida Atlantic University. Mr. St. Louis is reachable via email at pstlouis@thorntontomasetti.com.
Dr. Lauren Millman, Ph.D., PE, is an associate with Thornton Tomasetti Inc. (TT) in Fort Lauderdale, Fla. Dr. Millman has been with TT for eight years and specializes in forensic structural and materials engineering. She has a bachelor’s degree from the University of Florida and master’s and doctorate degrees from the University of Miami. Dr. Millman can be reached via email at lmillman@thorntontomasetti.com.
Ken R. Maschke, PE, SE, P.Eng., LEED AP, leads the renewal and forensics practices for Thornton Tomasetti Inc. (TT) in Toronto, Ont. He has over 17 years of experience in building failure investigation, structural rehabilitation, recladding, and adaptive reuse projects. Since his college days at the University of Michigan, Ken has enjoyed sharing his deep enthusiasm for the engineering profession. He has participated on the American Society of Civil Engineers’ Committee on Pre-College Outreach, the Sustainable Energy Initiative (SEI) Sustainability Committee, and the editorial board of the journal of Leadership and Management in Engineering.
