Factors That Influence Your Roof's Wind Resistance
Strong winds can rip your roof to shreds if you don't have the right roof design. If you are planning to install or replace a roof, you should talk with the contractor about your concerns about wind damage. Below are some of the factors the contractor can control to give you a wind-resistant roof.
The wind resistance of roofing materials determines how much wind uplift each material can withstand. For example, a 1-60 rating means that a material can withstand uplift forces of up to 60 pounds per square foot for sixty seconds. A 1-90 rating, on the other hand, means a material can withstand wind uplift forces of up to 90 pounds per square foot for 90 seconds.
A roof's design determines how much wind can get under the roof and cause damage. A roof design with multiple slopes withstands damaging wind forces better than those with fewer slopes. This is why hip (four-sided) roofs have better resistance than gable (two-sided) roofs.
Both flat and steep roofs have bad resistance — gentle slopes are the best. According to omnicalculator.com, a roof in a windy area should have a slope of 4/12 - 6/12 (4 inches rise for every 12 inches of run to 6 inches rise for every 12 inches of run). Anything outside that range exposes your roof to wind damage.
Wind damage generally comes from the uplift forces. This means the destructive forces of wind generally come from below. The greater the surface area the wind can latch on, the more damage it can cause. Roofs with lengthy overhangs (the section of the roof that extends over the walls) have more surface area for the wind to latch onto. Thus, short overhangs are best for wind resistance.
Strong winds can easily lift the whole roof and cast it aside if the roof-wall attachment is not strong enough. For example, using hurricane straps to connect the wall framing to the roof rafter is much stronger than using ties for the same. According to hunker.com, the straps can withstand wind forces of up to 100 miles per hour if you use them correctly.
Lastly, you should also use strong underlayment that won't easily tear when wind acts upon it. For example, synthetic underlayment is more resistant to wind damage than felt underlayment.
Once you have the right roof design, maintain it properly to minimize the risk of damage further. For example, you should trim trees around the house so that they don't fall on your roof and cause secondary damage.
For help preparing your roof for high winds, contact a roofing company like JC Roofing & Insulating in your area.