1. What is Roof Slope?

The roof slope (or pitch) is the steepness of a roof expressed as a ratio of vertical rise to horizontal run. It's a crucial factor in roof design affecting drainage, material selection, and structural requirements.

2. How Does the Calculator Work?

The calculator uses the basic slope formula:

Where:

• \( \text{Rise} \) — Vertical height (in feet or meters)
• \( \text{Run} \) — Horizontal distance (in feet or meters)

Additional Calculations:

• Slope Angle = arctan(Slope) in degrees
• Slope Percentage = Slope × 100%

3. Importance of Roof Slope

Details: Proper roof slope ensures effective water drainage, prevents leaks, determines suitable roofing materials, and affects the roof's aesthetic appearance.

4. Using the Calculator

Tips: Enter the vertical rise and horizontal run in the same units (typically feet). The calculator will provide the slope ratio, angle in degrees, and percentage grade.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between slope and pitch?
A: In roofing, pitch is typically expressed as a fraction (rise/run) while slope is often expressed as a ratio (X:12) or percentage.

Q2: What is a common roof slope for residential homes?
A: Most residential roofs have slopes between 4:12 (18.43°) and 9:12 (36.87°).

Q3: How does slope affect roofing materials?
A: Low-slope roofs (under 2:12) require special waterproofing, while steeper slopes can use standard shingles.

Q4: What's the minimum slope for water drainage?
A: Generally 1/4" per foot (1:48 slope) is the minimum for proper drainage.

Q5: How do I measure rise and run on an existing roof?
A: Measure the horizontal distance (run) from the edge to the peak, and the vertical distance (rise) from the attic floor to the peak.