Question: how do you calculate the slope of a flat roof?
Answer: The slope of a roof, or "pitch," is determined by how many inches the roof rises over 1 foot or 12 inches. An example for a steep sloped roof is 8:12. This means that the rise of the slope goes up or down 8 inches for every 12 inches. To put it in perspective, the angle of this slope would be around 30 degrees.