Why should petal edges on shingles be rounded off?

Rounding off the petal edges on shingles is crucial primarily to prevent wind uplift. When shingles are installed, especially in areas prone to high winds, sharp edges can create points where airflow can catch and lift the shingles. By rounding the edges, the airflow is smoothed, reducing the likelihood of the shingles being lifted by wind. This strategy enhances the overall performance and durability of the roofing system, ensuring that the shingles remain securely in place even under challenging weather conditions.

While aesthetic appeal, ease of cutting, and material strength are all valuable considerations in roofing, they do not address the specific structural and functional needs in relation to wind resistance that rounding edges accomplishes.