Winds are the most well-known attribute of hurricanes and tropical storms. Florida is one of the regions subject to high-wind conditions which can cause sudden, devastating property damage. The roof is an easy target for unpredictable and powerful wind forces because of its location on top of a home.
As such, it’s important when choosing roofing materials to go for one that can withstand severe wind events and minimize the chance of damage.
Asphalt Shingles
3-Tab Shingles
3-tab asphalt roofing shingles are the most popular roofing material because they are less expensive than their counterparts. However, they are only designed to withstand winds up to 110 mph with some versions only having a wind resistance of 60 mph.
If your home is in a wind and hurricane-prone area, you may want to install your asphalt shingle roof with nails rather than staples. The number of nails should also be increased to secure the roof in a way that reduces damage from winds.
Choosing 3-tab asphalt shingles because of their cost-effectiveness might not be a great idea because of the frequent need for replacement. Realistically, an standard asphalt shingle roof in Florida’s harsh weather will only last about 15 years. You may opt to install further reinforcement to your shingle roof, but this can be quite costly.
Architectural Shingles
Architectural asphalt shingles, on the other hand, may be a great option for your Florida home! These shingles are 50% heavier than their 3-tab counterparts. Because of the extra weight, these shingles are much more substantial and can withstand greater wind speeds. They also feature a thicker mat at the bottom, which makes tearing less likely in high wind scenarios.
Owens Corning Duration™ shingles are premium architectural shingles. They are sturdy and can withstand wind speeds of up to 130 mph. They are a great choice for homeowners that would like to keep the look of asphalt shingles while adding greater protection for their roofs in hurricane-force winds.
Metal Roofing
When it comes to wind resistance, metal roofing offers the best in durability, strength, and resistance to major storms. The large sheets or panels perform the best in storm conditions as opposed to small shingles or tiles.
The interlocking method of installation reduces the number of seams and overlaps. This stops high winds from getting their way underside of the panels.
When installed properly, a metal roof can withstand hurricane-force winds of up to 160 mph, making it one of the safest, most secure roofing options for hurricane-prone areas. While metal roofs are pricier than asphalt shingles, they are more durable and tend to last longer than any other type of roofing.
Concrete Tile
In areas prone to hurricanes, tornadoes, and extreme winds, concrete tile roofing provides defense against wind-related damage. In fact, concrete tile is one of the most popular roofing materials chosen by homeowners in Florida.
While not as strong as metal roofing against strong winds, concrete tile roofing can resist winds up to around 130 mph, which would strip off many other roofing materials. Their advantage in wind resistance is due to their shape and construction, which creates natural air ventilation under the tile and greatly reduces wind stress.
The individual pieces are attached most often with clips, wire, or concrete. Tiles at the highest roof pitch are fastened using screws to protect against high winds that can cause tile to blow away. But tile roofs are not without their disadvantages. During hurricane events, flying debris can break the tiles, making substantial repairs necessary.
How Wind Interacts with a Roof
Wind doesn’t always move in a steady stream; it moves in circular patterns and swirls up and down at various speeds in reaction to differences in temperature and pressure in the atmosphere, and variations in the land’s terrain and topography.
When wind encounters a structure, it can hit the side of the home and travel up and over the roof’s surface, with varying degrees of uplift pressure. This pressure is highest along the roof edges and at the corners of the roofline, which makes these areas more susceptible to wind damage.
As the wind moves over the roof surface, the air pressure directly above the roof decreases. This is known as negative pressure or suction pressure. Simultaneously, the wind causes infiltration in the building below through cracks and openings, which create positive pressure.
The combination of positive and negative pressure results in a “push-pull” force which may suck up or lift roofing materials off the roof decking.
Factors Affecting Wind’s Impacts on a Roof
Several factors influence how a roof may be impacted by wind. These include its direction and speed when it encounters your roof.
Roof Geometry
Steep slope gable roofs are more susceptible to wind uplift than low slope four-sided roofs.
Fastening Methods
The quality, strength, and number of fasteners used can also play a significant role in a roof’s ability to resist wind.
Installation Flaws
Incorrect nail placement, misaligned roof coverings, improperly installed underlayment, or poorly sealed flashing can reduce the roof’s performance in high wind events.
Local Weather
Your roof is more vulnerable to damage if you live in the High-Velocity Hurricane Zone region or where high winds occur frequently.
Testing Standards for Wind Resistance
To ensure a correctly built roof, there are several wind uplift tests used by manufacturers to test their roofing materials. These tests are designed to understand how the material can withstand both internal and external pressure. The most common testing methods include:
- Underwriters Laboratories (UL) 1897
- Underwriters Laboratories (UL) 580
- American Society for Testing and Materials (ASTM) E 1592
- Factory Mutual (FM) Global Standard 4471
The tests provide a rating reflecting the highest wind speed the roofing material can resist before failing. A point of system failure occurs when the roofing material detaches from the underlying roof decking.
How Can We Help?
If you’re looking for a roofing material that can withstand the high winds and diverse weather conditions of Central Florida, the experts at Alan’s Roofing are here to help you in your decision-making. Contact us today to learn more about our roofing services.
