Hurricanes Harvey, Irma and Maria made global headlines as they ravaged island nations and the southern part of the United States. The Category Four and Five hurricanes wiped out communications completely in several areas and knocked out power to millions. Hurricane Maria put the entire island of Puerto Rico into a power outage. While nothing can guarantee complete safety in natural disasters, science offers some ways that those living in coastal areas can be better prepared for hurricanes, typhoons and excessive flooding.
Civil engineers around the world have spent years analyzing what styles and shapes of houses outlast others. Engineer Rima Taher with the New Jersey Institute of Technology developed a major study in 2007. The study came two years after Hurricane Katrina devastated the New Orleans area.
"Although I'd like to say that there is a simple and economical solution for housing that won't fail or collapse in the perfect storm, such information does not yet exist," said Taher. "However, it is obvious that thanks to the work of wind engineers and researchers that changes to home design and construction can make buildings safer for people, while saving government and industry billions of dollars annually."
Here are some of the consistencies found in long-standing houses:
Square floor plans with a multi-panel roof
Square floor plans, hexagonal plans and even octagonal plans with four or more roof panels can greatly reduce wind loads. A 2016 study done by researchers at James Cook University found that modern 'trendy' roof patterns can sacrifice safety for style.
"The current building standards can underestimate suction pressures on roof edges of houses with complex roof shapes, and more so for two-story houses," said JCU researcher Korah Parackal. The team also reported that most building designers only assume one "worst-case" wind direction. While the report notes that not every designer can predict each eventuality, poor planning can leave houses devastated -- even to the smallest detail.
"Our wind tunnel research has shown the margins for error are not as great as many people think and underlines the need for builders and apprentices to be aware that very small defects in construction can get you in very big trouble," Parackal said.
Strong connections between roofs to walls
Most of the force winds put on a house will be uplifting forces. That makes sense given the countless images of roofs and roofing shingles being blown off of houses with ease. Prior to Hurricane Andrew, the state of Florida allowed for roofs to be stapled to the walls of the house. Andrew caused some of the most damage in the state's history, enough to ban stapling roofs in 1993.
Roofs with multiple slopes (like hip roofs)
Gable roofs might be significantly cheaper to build than a hip roof but they're considerably weaker. They easily peel off as the overhang catches wind like an umbrella catching a strong draft. The pressure gets multiplied under the overhang, exerting more pressure on both the triangular wall and the connecting roof edges. They might be trendy architecture, but that trend doesn't hold up against a hurricane.
Hip roofs (like the ones below) don't give strong winds a foothold as all sides slope down to meet a connecting wall.
Shorter roof overhangs
Most civil engineers agree that roof overhangs should be limited to 20 inches (51 cm). Anything longer could subject homeowners to strong wind uplift forces. As previously mentioned, those forces can compromise the entire roof.
Elevated homes serve a purpose beyond nicer views and aesthetics. 'Stilt' houses have been in coastal areas for centuries and for good reason. They can save houses from extensive flooding. During hurricanes and other natural disasters, one problem snowballs into another. Several feet of water damage not only lead to structural issues but compromise electrical circuitry, A/C and property loss.
A 2009 study done by Newcastle University even recommended that homeowners start looking to stilt houses in order to prepare for the rapidly changing weather patterns due to global climate change.
Science-approved and research-tested doors/windows
Why save the strongest doors for a small safe room when a homeowner could prepare an entire house? The Kiesling Wind Science and Engineering Research Center at Texas Tech created a list of the strongest doors and windows on the market. These doors range in style and type. Residents of the United States can also check their windows against the Federal Emergency Management Agency (FEMA) approval list.
Strong garage doors
One of the weakest points in a traditional house is the garage door. Once it goes, high-speed winds and rain can pressurize a house. That high pressure can weaken roofing connections and, in a few moments, a roof can pop off the house. Consumer Reports recommends homeowners have garage doors built to withstand 50 or more pounds of pressure per square foot. Single doors have much better chances of survival than double-door units.
Shuttering All Windows and Covering Them
There's an older myth that opening up windows during high-wind events like tornadoes and hurricanes levels out the pressure inside a house. It does the exact opposite, often leading to higher pressure in the house. Open windows also allow easy access to high-speed debris as they fly into a home.
Hundreds of thousands of people boarded up their windows prior to the triad of hurricanes within the last month. However, there are ways to make that even safer. Window clips (like PlyLox Windstorm clips) are screwless and nailless alternatives. They snap onto plywoods of various thicknesses. Users simply lodge the clips into the window space and the serrated part of the clip bites into the window casing.
While these clips don't guarantee safe windows during the strongest hurricanes, they can withstand impact and pressure resistance up to 150 mph in most cases.