1. What is Slope Ratio?

Slope Ratio represents the steepness of a roof as a ratio of vertical rise to horizontal run. It's commonly expressed as a ratio like 4:12, where 4 is the vertical rise and 12 is the horizontal run.

2. How Does the Calculator Work?

The calculator uses the slope ratio formula:

Where:

• \( \text{rise} \) — Vertical change (in feet)
• \( \text{run} \) — Horizontal change (in feet)

Explanation: The formula calculates the ratio of vertical rise to horizontal run, which determines the steepness of a roof.

3. Importance of Slope Ratio Calculation

Details: Accurate slope calculation is crucial for proper roof design, water drainage, material selection, and building code compliance.

4. Using the Calculator

Tips: Enter both rise and run values in the same units (typically feet). Both values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is a common roof slope ratio?
A: Common residential roof slopes range from 4:12 to 12:12, with 4:12 being a low slope and 12:12 being a very steep slope.

Q2: How is slope ratio different from slope percentage?
A: Slope ratio is expressed as rise:run (e.g., 4:12), while slope percentage is calculated as (rise/run) × 100%.

Q3: Why is roof slope important?
A: Roof slope affects water drainage, snow load capacity, material suitability, and overall building aesthetics.

Q4: What's the minimum slope for different roofing materials?
A: Asphalt shingles typically require at least 4:12 slope, while metal roofing can work with slopes as low as 1:12 with proper installation.

Q5: How do I convert slope ratio to degrees?
A: To convert ratio to degrees, use the formula: angle = arctan(rise/run). Many online calculators can perform this conversion.