Tornadoes and Roof Damage
While tornados aren’t a terribly common weather event in Virginia, they still make an appearance from time to time. When they do, the damage they cause to homes can be alarming. These damages can range from strong winds, to utter devastation to buildings and homes in the tornado’s path. With some extreme storms, there is no way to prevent or protect from damage, but with many tornadoes in the lower categories, if precautions are taken, structures come through fairly well.
It always seems to be after disaster strikes that we all wish we had taken the time to invest in the structure and durability of our homes. So why wait until then? We have the ability to prepare our homes, including the roofing, in order to ensure their lasting structure.
Don’t be caught off guard. There are a number of ways that you can prepare your roof to be protected from the weather effects of a tornado.
Why Tornadoes Are A Threat To Your Roof
Tornadoes can come in all shapes, sizes and intensities, bringing a variety of weather along with them. The severity of tornadoes is classified using the Enhanced F Scale:
F0/F1: 110 mph wind gusts and causes minor damages such as broken tree limbs.
F2/F3: Wind speeds up to 165 mph and strong enough to overturn cards, tear off roofs, and uproot trees.
F4/F5: Wind speeds up to 261 mph and able to level homes, hurling cars and debris with deadly force.
Their sizes typically range from 250 feet to two miles in diameter, giving them the ability to travel multiple miles across the ground before dissolving. If your home is in or near the tornado path, you’ll want to be prepared for the multiple ways it can cause damage to your roof.
Wind is the most common cause of roof and home damage during a tornado and usually occurs in one of two ways. In lower intensity storms, wind can rip multiple shingles off of a roof, or cause them to lift or crack. This opens up the roof to water damage, leaks, and UV damage, and needs to be fixed as soon as possible in order to minimize the extent of the damage and repairs.
Wind speeds of 100 mph are high enough to significantly impact your roof, and while low on the intensity scale, even a strong F1 tornado can have winds that exceed that speed.
When a tornado falls within the F2-F3 category and above, the wind can grow strong enough to take the entire roof off of a building. This is because the fast moving air from a tornado creates low air pressure while the air inside of a building is still.
The difference in air pressures can cause the roof to lift, pulling toward the lower pressure zone. This same principle that lifts a heavy plane into the sky causes a roof to be lifted off a home, is also the reason that windows could burst.
As high winds pick up debris and send it flying, it can land on your roof, causing significant risks. Items such as tree branches, trash, and other potentially dangerous items can be picked up by the wind and hurled into your roof, causing dents, broken shingles, or a caved-in roof depending on the size of the debris and the speed it is travelling at impact.
Hail often accompanies tornadoes, and once it reaches 1 inch in diameter, most roofs begin to sustain damage. A sustained hail storm, such as what may happen during a tornado, can cause shingles to break, split, crack and shed the protective granules. This breaks the seal of the roof and leaves it susceptible to water intrusion, subsequent leaks, mold, and other forms of water damage.
Ways To Prevent Tornado Damage
Depending on the severity of the storm, roof damage may be inevitable. However, there are still steps you can take to prevent it as much as possible.
Choose your roofing materials well
If you are building a new house or replacing the roof on an older house, and live in an area with frequent tornadoes, consider the roofing material you are installing.
Consider choosing wind resistant shingles for maximum protection. Shingles on the market have varying degrees of wind ratings, with the highest typically landing around 130 mph. Wind resistant shingles are made with a stronger adhesive layer between the shingle and granule, as well as a stronger mat, or base layer, typically made of an innovative fiberglass material. The combination of these materials give your shingles and roof a better chance of staying put during a tornado.
Metal roofs withstand hail storms better than traditional shingle roofs because they are strong enough to withstand the impact of hailstones. While visible denting may occur depending on the size of the hailstones, in most cases, that damage is purely cosmetic and does not affect the functionality or waterproof seal of the roof.
Slate roofs, both traditional and synthetic, are highly wind resistant options to consider. Slate roofs are resilient when it comes to weather extremes, and it is nearly impossible for wind to get underneath the material and lift the roof. While traditional slate roofing material is heavier than most homes are able to support, synthetic slate is much lighter while still providing the durability and wind resistance that comes with traditional slate.
Opt for multiple roof slopes
Two-slope gable roofs are common, but they are not the most wind-resistant choice for a roof. High wind forces can cause roofs to lift from your home, but roofs with 4 or more roof planes, such as the popular hip roof, perform better than popular 2 panel gable roofs when exposed to high wind force. These roofs are a great option for homes in regions susceptible to tornadoes.
Connect your roof to your walls
Making sure that the roof of your home is well-connected to the walls is critical when designing a tornado-resistant roof. Many homeowners’ insurance companies view a strong roof to wall connection as one of the most important factors in minimizing wind damage sustained by a home because the house is stronger when it functions as a connected unit.
While a strong connection is a requirement in most new homes, older homes did not have the same standards. Installing clips, straps, or brackets that connect the roof to the walls gives the roof increased stability, because the weight of the walls and foundation of the home will work to keep the roof in place. This will lessen the likelihood of the roof lifting in the event of a tornado.
Secure Outdoor Property
Besides direct repairs and updates to your roof, there are additional ways you can ensure the safety of your roof during a tornado. A significant amount of damage happens when flying objects impact the roof. Taking time to secure any loose objects around your home, such as fallen tree branches, children’s toys, planters or other small objects will minimize the risk of objects being picked up by the wind and slammed into your roof at high speeds.
Cenvar Roofing Helps Protect Your Roof
If your home has experienced damage from a tornado, or you are concerned about its ability to withstand tornado damage in the future, Cenvar Roofing would love to serve you. We specialize in roof repairs of all types, as well as roof replacements on homes all over Virginia. Schedule your free estimate today.