Pitch (roof)

Definition: Roof pitch refers to the steepness or slope of a roof, expressed as a ratio of the vertical rise to the horizontal run. It indicates how much the roof rises vertically for every 12 inches of horizontal distance. For example, a roof with an angle of 4:12 rises 4 inches for every 12 inches of horizontal run. Roof pitch is a critical factor in determining the roof’s design, the types of materials that can be used, and its overall performance in shedding water and snow.

Roof Pitch Measurement:

• Ratio: Roof slope is most commonly expressed as a ratio (e.g., 4:12, 6:12), where the first number represents the vertical rise, and the second number represents the horizontal run. The steeper the pitch, the higher the first number in the ratio.
• Degrees: Roof slope can also be measured in degrees, where the angle of the roof slope is expressed in relation to a horizontal line. However, the ratio method is more commonly used in the roofing industry.

Types of Roof Angle:

• Low-Slope Roofs (0:12 to 3:12)
• Moderate-Slope Roofs (4:12 to 6:12)
• Steep-Slope Roofs (7:12 and above)

Examples of Roof Pitch:

• 4:12 Pitch: This is a common residential roof incline, offering a balance between effective water runoff and a walkable surface for maintenance.
• 6:12 Pitch: A steeper pitch that provides better water and snow shedding capabilities while still being aesthetically pleasing for many architectural styles.
• 12:12 Pitch: A very steep roof, rising at a 45-degree angle, often seen in Gothic or Tudor-style architecture. This pitch allows for quick shedding of water and snow but is more challenging to walk on for repairs.