1. What is Roof Pitch?

Roof pitch is the steepness of a roof expressed as a ratio of vertical rise to horizontal run, or as an angle in degrees. It's a critical measurement in roofing that affects water drainage, material requirements, and structural design.

2. How Does the Calculator Work?

The calculator uses the roofing pitch formula:

Where:

• \( Rise \) — Vertical height (feet)
• \( Run \) — Horizontal distance (feet)
• \( \arctan \) — Inverse tangent function

Explanation: The calculator takes the vertical rise and horizontal run measurements, calculates the angle using the inverse tangent function, and provides results in both radians and degrees along with the pitch ratio.

3. Importance of Roof Pitch Calculation

Details: Accurate roof pitch calculation is essential for proper water drainage, selecting appropriate roofing materials, determining structural requirements, and ensuring building code compliance. Different pitches are suitable for different climates and architectural styles.

4. Using the Calculator

Tips: Enter the vertical rise and horizontal run measurements in feet. Both values must be positive numbers. The calculator will provide the pitch in radians, degrees, and as a ratio (rise:run).

5. Frequently Asked Questions (FAQ)

Q1: What is a common roof pitch for residential buildings?
A: Most residential roofs have a pitch between 4:12 and 9:12 (18-37 degrees), which provides good drainage while maintaining aesthetic appeal.

Q2: How do I measure rise and run for an existing roof?
A: For rise, measure vertically from the top of the wall plate to the highest point under the roof. For run, measure horizontally from the outside edge to the center of the roof.

Q3: What's the difference between pitch and slope?
A: Pitch is typically expressed as a ratio (rise:run), while slope is often expressed as a percentage (rise/run × 100%). Both describe the steepness of a roof.

Q4: Are there minimum pitch requirements for different roofing materials?
A: Yes, different materials have different minimum pitch requirements. For example, asphalt shingles typically require at least 4:12 pitch, while built-up roofs can work with much lower pitches.

Q5: How does roof pitch affect material requirements?
A: Steeper pitches require more roofing material for the same footprint due to the increased surface area. They may also require additional fastening and underlayment for proper installation.