Types of Tornadoes and Rebuilding After They Strike

Tornadoes can strike without warning, severely damaging homes, businesses, and other properties, in addition to threatening health and safety. Despite their speed, the damage they leave behind can linger, as regions and entire communities work to pick up the pieces and put their lives—and livelihoods—back together. But after cleanup and restoration take place, how exactly does the rebuilding process occur?

How Do Tornadoes Form?

Before detailing rebuilding and construction protocol after tornadoes and high-wind events, let’s establish the different types of tornadoes in the first place. According to the NOAA National Severe Storms Laboratory, tornadoes form from two types of thunderstorms: supercell and non-supercell.

Supercell thunderstorms (the most common type) tend to produce the most dangerous tornadoes, which stem from a rotating updraft in the wind.

Conversely, non-supercell thunderstorms account for about 20% of all tornado formation. These types of tornadoes often occur in the early morning or late at night, and tend to be shorter in duration and weaker than supercell-formed tornadoes.

What Types of Tornadoes are There?

As you watch the news or hear certain tornado terms, you may be wondering what they mean. AccuWeather details 10 types of tornadoes that occur in the United States:

1. Wedge Tornado. These are some of the largest and most destructive tornadoes, as they can grow to more than a mile in diameter. They are sometimes called “ground scrubbers.”
2. Twin Tornadoes. Often called “sisters” and a rare weather phenomenon, this occurs when two tornadoes form side by side from two separate circulation areas.
3. Rope Tornado. Long, thin, and often the shortest-lived of the tornado types, rope tornadoes tend to cut a narrower path of damage, but they can still be very destructive.
4. Satellite Tornado. These are smaller funnels that accompany tornadoes and float around the area of circulation, similar to how satellites float around Earth.
5. Landspout. Formed by a column of spinning air near the ground, landspouts are not connected to a rotating thunderstorm at their base. While they can cause damage much like a tornado, they are often weak and relatively short in duration.
   1. They differ from dust devils, which can occur during sunshine and warm days, when no apparent storm is nearby.
6. Waterspout. Any tornado that forms over water is classified as a waterspout. Notably, they are often weaker than their land counterparts, and often look similar to rope tornadoes. Multiple waterspouts can occur in close proximity to each other.
7. Cone Tornado. Shaped like an ice cream cone, these tornadoes are very large at the top, then narrow toward the bottom. They can be very large and extremely destructive.
8. Stovepipe Tornado. Similar in size to a cone tornado, stovepipes differ in that they are generally the same width from top to bottom.
9. Elephant Trunk Tornado. Similar in size to a cone or stovepipe tornado, this type is slightly different in that it curves sideways, looking much like an elephant’s trunk.
10. Multi-Vortex Tornado. This is when a tornado has multiple rotation areas inside the actual funnel, rather than a single rotating column of air.

Repair and Rebuilding Tips After a Tornado

FEMA offers extensive guidance on how to repair and rebuild your property after a tornado. Tips include:

• Determine appropriate building codes for your area.
• Use best practices when engaging in reconstruction. This might include:
  • Sheathing. Debris can penetrate fireboard sheathing and even rigid insulation boards during high winds. Therefore, consider using oriented-strand board (OSB) or plywood. This will help protect the roof against debris.
  • Garage Doors. These can buckle inward or outward during a tornado. During the rebuilding phase, consider selecting doors built to withstand higher wind speeds.
  • Asphalt Shingles. Because these types of shingles can blow off in high winds (exposing your roof to rain), consider using shingles rated for 90 mph winds or higher. Additionally, it is recommended to use four or six nails per shingle to help prevent damage and offer significant protection to your property’s roof.
  • Roof-to-Wall Connections. During a tornado, these connectors might cause a partial or entire loss of the roof, and/or an uplift of the entire roofing system. Therefore, FEMA recommends using metal connectors to help make sure there is an unbroken load path from the roof to the foundation. These connectors should be approved for use with the appropriate wind speed.
  • Gable End Walls. These types of walls can rotate or collapse during heavy wind and tornadoes, causing walls to buckle. They might even cause hinges and entire sections of a building to fail, severely damaging the roof system. During reconstruction, consider adding more connectors (metal is ideal) and using more framing, to ultimately help improve the load path.
  • Brick Veneer. Because these can pull away from wall systems, consider using brick ties to attach veneers to the wall framing, using appropriate spacing.
  • Windows and Doors. Sometimes dislodged from walls during tornadoes, verify these are properly shimmed and nailed into the framed opening during the rebuilding phase. Use nails of proper length, tying the window and door frames into adjacent studs.
  • Baseplate or Sill Plates. Uplift from the wall system, as well as shear failures, make this an important part of reconstruction after a tornado. FEMA recommends adding anchor bolt connections between the plate and the foundation every four feet (or less).
  • Vinyl Siding. This type of siding can pull off wall sheathing during a tornado, so consider using vinyl siding rated for high winds; attach it to the wall framing.
• Additionally, consider adding or converting an existing room in your property to a safe room. This is oftentimes an interior room, but could also be a particular space within a building, or a separate building created specifically for the purpose of protecting occupants during intense storms, like a tornado or hurricane. Ultimately, a safe room should help protect against wind forces and debris.

After a Natural Disaster, SERVPRO ^® is Here to Help^®

Tornadoes are just one of many natural disasters that can strike with little to no warning. While a top priority is often to find shelter and safety as soon as possible, after the tornado or storm passes, you might be left with minor or major property damage. In the aftermath of tornadoes or other natural disasters, SERVPRO is here to help with cleanup, restoration, and construction on a 24-hour basis.

With 2260 SERVPRO locations in the United States and Canada, there is a SERVPRO near you, prepared to assist with both large and small jobs. As the #1 choice in fire and water cleanup and restoration*, rely on SERVPRO to help restore your property and get you back on your feet. With proprietary tools and equipment, and over 50 years of experience across the system, SERVPRO is committed to providing elite remediation services.

SERVPRO offers a variety of resources about the cleanup and restoration industry. To learn more, please visit our FAQ and Glossary.