According to the National Weather Center, severe thunderstorms are officially defined as storms that are capable of producing hail that is an inch or larger or wind gusts over 58 mph. Some can even produce softball-sized hail and 100-plus mph winds. Since thunderstorms can happen any time of the year and cause damage to your business, it’s important to watch the weather and prepare now with these steps to reduce your risk for loss or damage.  

1. Inspect and maintain your building’s roof

Start with your roof and its components. In the guide below, you will learn how to inspect and maintain your roof, whether you have a low-slope roof with a membrane, a steep-slope roof with shingles, or anything in between. You will also find guidance for roof components like drainage systems, flashing, roof-mounted equipment, and more.

2. Install HVAC hail protection 

Know what hail area your structure is located in. Even if you’ve checked in the past, it should be rechecked every few years since climate change has caused these high-risk areas to expand.  

Install protection such as hail guards, shields, or wire mesh. Be sure it is installed so it can also withstand wind forces common to your area. Make sure your contractor is knowledgeable about wind design requirements from the latest building codes.

3. Install a backup, surge, and/or lightning protection system

  • To help protect against dangerous lightning strikes to your property, which can damage buildings, and surges or failure of internal systems and equipment, install a lightning protection system.
  • Roof-mounted lightning protection systems should be designed and installed for wind resistance.
  • Lightning protection systems should be designed with high winds in mind. Closed loop connectors provide higher wind uplift capacities over the typical prong connectors. Speak with a licensed lightning protection contractor to install the proper system. For more information, visit the Lightning Protection Institute website at
  • Lightning systems may not protect you from all damage or give your building total protection.  
  • For surge protection, contact your local electric power company to install a surge protection system where the external power is supplied to the business. Surge protection systems regulate the voltage supplied to an electric device either by blocking or diverting voltages above a certain threshold safely to the ground. 
  • If you do not own the building, you will want to protect your equipment and contents. 
  • Add surge suppressors/protectors to the power connection of individual pieces of sensitive equipment and to any communications lines (e.g., phone cords, Internet cables, coaxial cables, etc.). 
  • Talk to the building owner to see if they will install backup power like uninterruptible power supply (UPS) batteries and a generator for important things like lights and refrigerators. A UPS is for computer systems to supply immediate emergency power for a short period of time so work can be saved and equipment can be properly shut down before a generator turns on.
  • Install battery backups for sump pumps to prevent water losses during power outages.

4. Consider stronger skylights 

To protect against hail and flying debris, skylights should meet at least one of the following rating requirements: 

  • ASTM E1886 cyclic pressure test requirements and be ASTM E1996 missile impact rated “B”, “C”, “D”, or “E”.     
  • FM Approved per ANSI/FM 4431, with Severe Hail rating.  
  • Current Miami-Dade County Approved (MDCA) Notice of Acceptance including impact resistance.

5. Prepare your windows

  • Check the seals around the windows and use sealants compatible with adjacent building materials to seal any cracks or gaps to keep water out.   
  • In some cladding and/or storefront systems there are weeps intended to stay open, which should not be caulked. 

6. Inspect and close your doors, roll-ups, garage, and/or overhead doors  

  • Check the brackets that connect the door frame to the structure. Make sure they are tightly secured, are not missing any bolts or nuts, and are not broken.  
  • Make sure there are no major dents, damage, warping and/or rusting.  
  • Check your roll-up doors for their wind label. If there are no labels, contact a commercial door contractor to determine if you have the proper door for your area. If not, consider replacing it with the proper wind-rated door. 
  • When thunderstorms are in the forecast, close exterior overhead doors, garages, roll-ups, and windows to keep out rain and wind. These are large openings, which is an added risk to potential building damage. Also close all interior doors to give your roof a fighting chance in a high-wind event. 

7. Secure outdoor equipment, signage, inventory, and loose items

  • When subjected to high winds, unsecured objects such as pallets can become flying debris, causing damage to your building or surrounding businesses.  
  • Make sure sign connections have no missing bolts or screws and are free from rust.
  • Due to COVID pandemic restrictions, some businesses have adapted by temporarily moving their services outside (i.e., restaurants). Make sure to watch the weather forecasts closely to determine when you should move inventory indoors.  

8. Maintain landscaping

  • Keep all trees trimmed and away from the roof and building. Ungroomed trees with branches near your building can damage the roof cover, siding, and windows, and can also clog roof drains.
  • Pay particular attention to trees within falling distance of overhead power lines leading into the property. Avoiding a power outage can save a day or two of business interruption.

9. Review your insurance and make a plan  

  • Review your insurance policy and know what it covers—and what it doesn’t. 
  • Store your insurance agent’s contact information in your phone.
  • Create a business continuity plan with OFB-EZ  (Open for Business-EZ). This tool helps your business plan for any type of business disruption, so you can quickly re-open and resume operations following a disaster. 
  • Create an emergency preparedness and response plan with the IBHS EZ-PREP tool. Note that timelines for severe thunderstorms are much shorter than for hurricanes.  

10. Get reliable weather information and alerts 

  • Having a system in place helps you, your employees, and customers react quickly in an emergency, like a tornado warning. Do NOT rely on outdoor sirens to alert you. 
  • Find a reliable source for severe weather information. Pay attention to severe weather outlooks from NOAA’s Storm Prediction Center (SPC). Follow the SPC on Facebook or Twitter and tune in to local news often when severe weather is forecast. 
  • Enable wireless emergency alerts on your cell phone. 
  • Purchase a weather alert radio that broadcasts emergency alerts from the National Weather Service, preferably one with a hand crank. These radios can alert you when you are sleeping and don’t rely on electricity or cell service. 



Car dealerships, garden centers, shed and outbuilding retailers, and others whose inventory is largely kept outside can suffer significant damage to inventory.  

  • Understand your risk and properly implement an emergency action plan to shelter products when hail is forecast.  
  • Routinely practice or conduct sunny-day drills so your employees can act quickly to protect your investment in inventory.  

Agricultural Farms

Hail damage to farms can be significant and sometimes economically crippling.  

  • When thunderstorms are in the forecast, protect your expensive machinery and tractors from hail by moving them inside a storage shed. Shutting storage shed doors when high winds are expected may also help to prevent increased internal pressures in the structure.  
  • While preventing damage may not be possible, federal crop insurance is available. Learn more from the United States Department of Agriculture. 

FORTIFIED Commercial

If you’re looking to replace your roof, consider building stronger with FORTIFIED Commercial™.