Hurricane-force winds cause major damage to roofs through pressure on the overhangs by strong updrafts, resulting in billions of dollars in damages.

The aim of this project is to fix current roof designs to be more resistant to hurricane-force winds by engineering models of roof components and simulating low force winds on the models to test for a sturdier roof design.

Hurricanes are major natural disasters that can cause damage to buildings. These storms produce high winds, heavy rain, and low pressure that can severely damage most infrastructure. Storms are deemed hurricanes based on their wind speed and not their rain; they reach hurricane status when they have sustained wind speeds of over 74 miles per hour. Storms under 74 miles per hour are considered tropical storms or tropical depressions. Hurricanes are strongest over water, but as it moves inland to where more people live, they become weaker. The government costs of hurricane damage each year are on average $28 billion dollars. This will likely increase due to climate change, as hurricanes become more severe, with cost estimates reaching $39 billion by 2075. The increase in severity comes from ocean waters warming, which feeds energy into the hurricane. In addition, major hurricanes can kill hundreds or thousands of people, some examples being hurricane Katrina causing the deaths of 1,836 people and hurricane Maria killing 2,975 people. Buildings are made up of many different components. Some examples of components are the foundation, the framing of the building, and the roof. The foundation is at the bottom of the structure and supports the entire weight of the building. Because the foundation is in direct contact with the ground, it is often shielded from the wind, and would only be a problem if the building was lifted off of the ground. A more vulnerable component of a building would be the roofs. Out of the many components of buildings, hurricanes affect roofs the most. Roofs are a component that is on top of a building. Most residential roofs are made out of a wooden frame, with asphalt shingles on top. A roof itself has many different components, including purlins, rafters, gables, corners, end bays, and eaves. Corners, end bays, and eaves are parts of a roof that overhang off the main building. A study in 2016 found that when the wind was parallel to the direction of the purlins, the main failure was in the corners and end bays, and when the wind was perpendicular to the direction of the purlins, the main failure was in the eaves. These overhangs are the main cause of roof failure, and they are what this project focuses to improve.

The models were designed in Solidworks and were 3-D printed using PLA plastic. The base model measures 9x9 cm and each of the roof pieces are 1cm wide. There were four model designs. Model 1 has a standard 1 cm overhang, model 2 has a 1 cm overhang with a modification piece, model 3 has a 2 cm overhang, and model 4 has a 2 cm overhang with a modification piece. A custom wind tunnel was created to test wind speeds. It was built out of styrofoam and plexiglass and is powered by a leafblower. The models were placed at the far end of the wind tunnel and were slowly pushed towards the leafblower to simulate increasing wind speeds. When a model piece is blown off, the model stops moving and its position is recorded. This process was repeated 15 times for each model, resulting in 60 data points. Each position is then measured with an anemometer to measure the wind speed. These speeds are then averaged out to find the average maximum wind speed.