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.