More than ever before, building design and construction can be significantly improved to reduce wind pressures on building surfaces and to help better resist high winds and hurricanes in residential or commercial construction, said NJIT architecture professor Rima Taher, PhD. Taher, who is also a civil/structural engineer, teaches at the New Jersey School of Architecture. Courses taught by her include topics related to wind and earthquakes with guidelines and recommendations for better design and construction in hurricane and earthquake prone areas.
“Certain home shapes and roof types can make a big difference,” she said.
She recommends the following for anyone building in high wind regions.
Design buildings with square, hexagonal or even octagonal floor plans. “Such designs reduce wind loads,” she said.
Roofs with multiple slopes such as a four-sloped hip roof perform better under wind forces than gable roofs with two slopes. Gable roofs are common only because they are cheaper to build. Research and testing show that a 30-degree roof slope has the best results, she said.
Wind forces on a roof tend to be uplift. “This explains why roofs blow off during extreme wind events,” she said. To combat uplift, she advises connecting roofs to walls with nails, not staples. Stapled roofs were banned in Florida after Hurricane Andrew.
Aim for strong connections between the structure and foundation. Structural failure is often progressive where the failure of one structural element triggers the failure of another. Connections can be inexpensively strengthened.
Roof overhangs are subject to wind uplift forces which could trigger a roof failure. In the design of the hurricane-resistant home, the length of these overhangs should be limited to about 20 inches.
The design of the researched cyclonic home includes simple systems to reduce the local wind stresses at the roof’s lower edges such as a notched frieze or a horizontal grid. Install the latter at the level of the gutters along the homes’ perimeter.
An elevated structure on an open foundation reduces the risk of damage from flooding and storm-driven water.
Taher also teaches some courses to help prepare architecture graduates for the Architect Registration Exam. She is the author of a new book about structural systems for the exam. Last year her article about the design of low-rise buildings for extreme wind events appeared in the Journal of Architectural Engineering.