Best Resilient Roof Design For Hurricanes

During hurricanes, your roof is one of the most vulnerable areas of your home. In the aftermath of some hurricanes, you often see images with several homes missing their roof.

If you live in the tropics, you have probably seen those hurricane preparedness videos where a roof goes flying off the top of a building, like a piece of paper.

Storms and hurricanes are a major concern of living in a tropical region. With climate change, these incredible forces of nature appear to be occurring more frequently and with increased ferocity. As such, it is becoming more important to design and maintain a home that is resilient to tropical cyclones.

The thought of losing your roof during a hurricane can be overwhelming. Wind and rainwater entering your home can create extensive damage to your home and possessions. I have seen instances where homeowners have even used ropes to tie their roof down before the arrival of a storm or hurricane.

This level of fear is merited since the loss of your roof can cause significant cost in damages to your home. It also creates an added stress of being displaced after the already traumatic experience of having gone through a severe weather event.

Researcher and university lecturer at the New Jersey Institute of Technology (NJIT), Rima Taher, PhD, researched low-rise buildings and their resistance to extreme wind events like hurricanes.

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If you are preparing to build a home and you are considering what type of roof design will be the most resilient against hurricanes, here are some things you can consider.

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Connection To Main Structure

One of the main reasons a roof might fail in high winds is because of weak connections between the roof and the main structure of the home.

The major wind forces on a roof tend to be from the uplift. Wind uplift on a roof occurs when the air pressure on the inside of your home is greater than that outside. When wind moves over a roof it decreases the pressure above the roof creating an upward pull.

Hence, a roof that is well built and properly connected to the main structure of your home, such as to the beam or wall plate is more likely to remain intact during a hurricane.

The stronger the connections used the better the integrity of the roof.

Metal straps and ties or hurricane straps should be used and properly secured to ensure a strong connection with the structural elements of the home.

Shape Of The Roof

A home and a roof that are close to being round are more likely to resist high winds. Hence, hexagonal or octagonal roof plans, with multiple sloped panels, tend to perform better.

However, a home that has a square floor plan and a roof with multiple panels also perform well. The multiple sloping panels that these roofs have are better at resisting high winds coming from multiple directions.

Rectangular or irregular shaped homes do not resist wind loads as well.

Type Of Roof

Hip roofs or roofs with four or more sloping panels are the most resistant to wind loads.

Though gable roofs tend to be popular, perhaps because they are more economical, they do not perform as well as hip roofs in an extreme wind event.

Hip roofs are more aerodynamic and resistant to uplift than gable roofs.

Roof Slope/Pitch

The test and research showed that a thirty (30) degree slope is ideal, according to Rima Taher.  The aerodynamics of this pitch performed the best.

Roofs with lower slopes tend to create greater uplift forces in high winds. While, with steeply pitched roofs, they create a wall or sail-like effect for wind loads to act on.

Overhangs

The eaves or overhangs of a roof are susceptible to uplift from wind forces as well.

Though eave overhangs occur on the exterior of your home, they are still connected to the main structure of your roof. If this part of your roof fails, it can compromise the integrity of the remainder of your roof.

Therefore, smaller overhangs are safer in high winds. In Dr Taher’s research, she recommends no more than a twenty-inch (20”) overhang. 

Conclusion

The roof is a major part of your home. In the tropics, it is critical to design it in a way that is resilient to wind loads experienced during hurricanes.

Consider using hip roofs that are either square or as round as possible. These are more aerodynamic and resist high winds more.

A 30-degree roof pitch or slope is ideal. Also, avoid creating roof overhangs that exceed 20 inches, as these can be more susceptible to the wind.

A properly built roof and home that is resilient to storms and hurricanes could save you a lot of expense after a severe storm event. The additional upfront cost to put resilient design measures in place can end up being a lot less than the damage a hurricane can cause to your home. It can also offer peace of mind to you and your family.

Featured image by Robin Kutesa on Unsplash