2010 – Florida Building Code

Chapter 27

NEW – Section 2706 Lightning Protection

2706.1 Lightning Protection. A lightning protection system shall be provided for all new buildings and additions in accordance with NFPA 780, Standard for the Installation of Lightning Protection Systems.

2706.2 Where additions are constructed to existing building, the existing building’s lightning protection system, if connected to the new lightning protection system, shall be inspected and brought into compliance with current standards.

2706.3 Surge protection devices shall be installed for all normal and emergency electrical systems in accordance with NFPA 70, National Electrical Code.

Exceptions:

1. One- and two-family dwellings

2. Lightning protection shall not be required for any building or addition where shown unnecessary by evaluation using the Risk Assessment Guide in NFPA 780, Standard for the Installation of Lightning Protection Systems or an alternative method approved by the authority having jurisdiction.

Substantiation:

1. According to the National Weather Service:
a. The are an average of 20 Million lightning strikes in the US each year
b. The average lightning strike delivers between 100 Million and 1 Billion volts of electricity
c. The average lightning strike delivers between 10,000 and 200,000 amperes of electricity.

2. According to the National Weather Service:
a. Between 1959 and 1993, 53.1% of all deaths in the state of Florida related to weather were due to lightning. This is more than drowning, tornadoes, hurricanes, wind and, cold combined.
b. During these same years, a total of 449 persons died in the state of Florida from lightning, another 1788 were injured. In comparison, the average number of deaths during this period nationwide is only 48.
c. The number of lightning deaths and injuries in the state of Florida outpaces every other state in the nation by 3:1.

3. According to the National Fire Protection Association:
a. There is an average of 70 to 100 thunderstorm days per year in the state of Florida. (National Weather Services)
b. There is an average of 8 to 14+ lightning strikes in the state of Florida for every square kilometer per year. (U.S. National Lightning Detection Network)

4. According to the National Lightning Safety Institute:
a. In 2008 alone, there were 246,200 insurance claims on residential structures in the US. Insured loses on residential properties exceed $1 billion dollars annually. (Insurance Information Institute, NY, press release, 6/22/09)
b. Lightning is responsible for more than $5 billion dollars in total insurance losses annually. (Hartford Insurance Co. – TMCNet Newsletter, Sept 14, 2006)
c. During 2002-2004, fire departments responded annually to about 31,000 fires caused by lightning with $213,000,000 in direct property damage. (NFPA Report, January 2008)
d. Looking specifically at storage and processing facilities, lightning accounts for 61% of the accidents initiated by natural events. 16 out of 20 accidents involving petroleum products storage tanks were due to lightning strikes. (Journal of Hazardous Materials 40 (1995) 43-54
e. 30% of U.S. businesses suffer damage from lightning storms. (Carnegie Mellon Report, 02/06)
f. 30% of all power outages annually are lightning-related, on average, with a total cost of $1 billion dollars. (Ralph Berstein, EPRI; Diels, et al (1997))

5. According to the National Oceanic and Atmospheric Administration
a. The average cost of lightning-caused damages in the US is between $5,000 and $50,000. (Storm Data)
b. Between 1959 and 1994, there were 17 lightning losses of over $5 million dollars. (Storm Data)
c. During these same years, 92 lightning losses exceed $500,000 dollars.

6. According to the Factory Mutual System:
a. Lightning related private sector property damage costs for the 1990-1992 period averaged $27 million annually.
b. Information complied by the nation’s fire chiefs indicate structural lightning losses at $138.7 million as average over 1989-1993.
c. There were 20,000 lightning-caused residential annually during that same period.
d. During the period of 1973-1982, there were 2,926 lightning claims for a total cost of $385 million dollars. Lost time from an idle workforce was not included therein.


Cost:

1. The average cost of a complete lightning protection system, including deign, materials, installation, and maintenance is approximately 1% to 5% of total construction cost of the building.

2. The average cost to renovate a building with lightning protection after completion of construction is approximately 10 times that of a new building under construction.

3. The cost of the lightning protection system can be off-set as much as 80% by insurance deductions and rebates.

4. Lightning risk assessment calculations are readily available free online and take approximately 15 minutes to complete.


Enforcement:

1. Standard and reference materials are readily available. The NFPA 780 is already a referenced standard in the FBC and mandated by section 419, 420, and 423.

2. Underwriter’s Laboratories offers lightning protection education for design professionals, installers, and enforcement officials. Systems installed under the provisions of NFPA 780 must be in compliance with UL96 and 96A.

3. UL has been testing and certifying lightning protection equipment since 1908. UL issues inspection certificates for systems by inspecting system components and checking completed installations. Installations are required to comply with UL's internationally recognized Standards for lightning protection systems.