Lightning protection code changes improve safety and resilience

A new tune

Although these exhausts are bonded to the lightning protection system, they would now have to be surmounted by air terminals. Additionally, the right-angle bends in the conductors would no longer be allowed.

While CSA B72 has been harmonized with other North American standards, each document has notes that are necessary to complete the melody. Therefore, the authors recommend a project specification also reference the following:

  • Lightning Protection Institute (LPI) 175, Standard of Practice for the Design – Installation – Inspection of Lightning Protection Systems;
  • NFPA 70, Installation of Lightning Protection Systems; and
  • the Underwriters Laboratories (UL) 96A, Installation Requirements for Lightning Protection Systems.

Taken together, these standards cover almost every condition encountered in conventional buildings. For example:

  • NFPA limits, with regards to wind resistance, the size of ornaments installed on air terminals, a topic unaddressed in CSA B72;
  • CSA B72 permits rooftop railings as thin as 3.2 mm (126 mils) to be used as strike termination devices, while UL 96A makes clear this also applies to rooftop ladders; and
  • NFPA provides extensive guidance on lightning surge protection, while CSA B72 offers only a short, non-normative annex on the subject.

In addition to codes and standards, the lightning protection industry is supported by organizations that certify individuals working in the industry and the quality of installations. As Larter explains that building, “designers should ensure lightning protection is installed by experienced, qualified firms with a demonstrable record of providing certified systems.”

The Lightning Protection Institute (LPI) has testing and certification programs to qualify lightning protection installers and designers. Additionally, the Lightning Protection Institute – Inspection Program (LPI-IP) performs third-party inspections and certifications of individual LPS installations. More information about these certifications is in the aforementioned article in Construction Canada.

Specifiers can rely on these codes, standards, and certifications as the basis for delegating LPS design. A project specification should require LPS to comply with the four codes and standards, the design to be prepared by an LPI-certified Master Installer or Master Installer/Designer, the installation to be performed by a firm with requisite experience and an LPI-certified Master Installer, and that the installation be inspected and certified by LPI-IP.3

These air terminals on the roof of a high-rise in Edmonton, Alta., do not rise 250 mm (10 in.) above the parapet rail as now required. Note that conductor cables are not required between the air terminals as the steel tube on which they are mounted meets the criteria to be used as a conductor.

By delegating design, it is not typically necessary to draw or detail LPS in contract documents. Drawings, however, should indicate the scope of the lightning protection if there are multiple structures onsite. They may also be necessary to explain special esthetic requirements, such as the alignment of air terminals with certain façade features or the use of metal fabrications as strike termination devices in lieu of air terminals.

Specifiers need note the latest edition of MasterFormat—the CSC and CSI standard for organizing construction activities by work results—has created new section numbers and titles for lightning protection of buildings, including:

  • 01 56 21 – Temporary Lightning Protection;
  • 13 01 46 – Maintenance of Lightning Protection; and
  • 13 46 00 – Lightning Protection Systems.

Lightning protection was in Division 13 – Special Construction prior to being moved to Division 26 – Electrical in the major revision of MasterFormat in 2004. Restoring it to Division 13 underscores:

  • an LPS is integrated with many other systems in a building; and
  • while lightning protection services are frequently subcontracted through electrical contractors, the requirements for and components of an LPS are much different than those that apply to building power systems.

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