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Designers, Manufacturers, Installers of Lightning Protection Systems Since 1898


As a full-service Lightning Protection System company, Dominion Lightning Rod Co. brings our broad experience to each element of a project.

Risk assessment map

Risk Assessment

Dominion Lightning Rod Co. Ltd. is qualified to provide a formal Lightning Damage Risk Assessment based on industry standards as outlined in the CSA B72-20 and NFPA 780.  These technical Risk Assessments have been developed and refined to provide a mathematically-based evaluation and recommendation based on project-specific conditions.

The following factors are evaluated:

  • Occupant Safety: liability for the safety of occupants
  • Nature of building/structure and contents: susceptibility of the building, historical value, replacement value, contents (value, environmental impact, flammability, etc.)
  • Relative Exposure to Lightning: topographical elements and surrounding building density
  • Lightning flash density: frequency and intensity of lightning storms in the area
  • Indirect Losses: consequences of loss such as business interruption or disruption of services provided by the structure.

The assessment quantifies two factors: the lightning threat evaluation and the tolerable lightning frequency.  The lightning threat evaluation determines the average lightning strike frequency for the structure using:

  • Lightning ground flash density for the specific project location using environmental data
  • Equivalent collection area of the structure using the length, width, and height of the structure and can account for a structure with a complex footprint
  • The location of the structure including topography and other structures within the collection area

The tolerable lightning frequency determines the risk tolerance for the structure using:

  • A construction coefficient taking into account the structure’s framework and components
  • A contents coefficient taking into account the value and combustibility of the contents
  • An occupancy coefficient taking into account the normal occupancy of the structure during peak lightning hours
  • A lightning consequence coefficient taking into account the requirement for continuity of service requirement and environmental impacts of a strike

Once the assessment is complete, a formal report is provided.

Risk Assessments assist architects and engineers in the early stages of projects in mitigating the dangers posed by lightning.