Shingle Blow Off | Nailing Patterns
Believe it or not shingle blow off is common when your roof is hit with high winds. Most shingles are nailed down with 8 nails, 4 when attaching a shingle, and 4 more when the next row goes on above. This is the most common nail pattern with most laminated shingles. Eight nails will usually hold down shingles in winds up to 70 miles per hour.
You can increase shingle adherence to 120 miles per hour by adding two extra nails per shingle. It is called hurricane nailing by the GAF Shingle Manufacturer, and is code in Dade and Broward County Florida.
If your asphalt shingle roof is up on a hill and not protected by surrounding structures, you will be more vulnerable to mother nature.
With traditional asphalt shingles, as each course goes on over the last, the piece of the shingle that is left exposed is measured. GAF Recommends a 5 inch to 5 3/4 inch exposure. Note* The longer the exposure the less shingles you will need to cover a roof.
The smaller 5 inch exposure creates better adherence and is less likely to get caught and torn off in a strong wind. Some contractors and builders will try to get maximum exposure, reducing material costs, and increasing profits.