Does your Building Require Lightning Protection?
NFPA 780 is the North American standard for lightning protection systems (LPS). It contains “Simplified Risk Assessment” calculations to determine if an LPS is recommended for a building.
East Coast Lightning Equipment, Inc.’s online risk calculator automates the calculations to make it even easier. It also prepares a report you can present to the building owner.
For more detailed information, see User Guide for Lightning Risk Calculator
How to Use the Online Risk Calculator
- Enter general project information.
- Sketch roof areas to show building’s general shape and size. Include large rooftop fixtures such as major pieces of equipment, antennas, etc. Enter height above grade for each building element.
- Click Map link to find lightning flash density.
- Use drop-down boxes to enter the required information, then press “Calculate”.
- A two-page PDF report will be generated showing the data and sketch you entered plus the calculations. Based on NFPA criteria, the report will make one of the following statements:
For more information, see User Guide for Lightning Risk Calculator
NFPA 780 states, “There are some cases where the need for protection should be given serious consideration regardless of the risk assessment. Examples are those applications where the following are factors:
- Large crowds
- Continuity of critical services
- High lightning flash density
- Tall isolated structure
- Buildings containing explosive or flammable materials
- Buildings containing irreplaceable cultural heritage
“Statutory, regulatory, and insurance requirements for the installation of a lightning protection system should take precedence over the results of a risk assessment.”
Discuss with Building Owner
Design professionals should discuss the risk assessment report with the building owner. If calculations or special considerations recommend a lightning protection system yet the owner decides against using it, the designer should get the decision in writing.