1. What is Roof Slope?

Roof slope, also known as roof pitch, is the steepness of a roof expressed as a ratio of vertical rise to horizontal run. It determines how quickly water drains off the roof and affects the roofing materials that can be used.

2. How Does the Calculator Work?

The calculator uses the fundamental slope formula:

Where:

• \( Rise \) — Vertical height (feet)
• \( Run \) — Horizontal distance (feet)

Additional Calculations:

• Roof Pitch: Slope ratio × 12 (standard in construction industry)
• Slope Angle: arctan(Slope) converted to degrees
• Slope Percentage: Slope ratio × 100%

3. Importance of Roof Slope Calculation

Details: Proper roof slope calculation is essential for water drainage, structural integrity, material selection, building code compliance, and aesthetic design. Different slopes are required for different roofing materials and climate conditions.

4. Using the Calculator

Tips: Enter the vertical rise and horizontal run in feet. Both values must be positive numbers. The calculator will provide slope in multiple formats including ratio, pitch, degrees, and percentage.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between slope and pitch?
A: Slope is the ratio of rise to run, while pitch is typically expressed as rise in 12 units of run (e.g., 4:12 means 4 inches rise per 12 inches run).

Q2: What are common roof slopes?
A: Flat roofs: 0:12 to 2:12, Low slope: 2:12 to 4:12, Conventional: 4:12 to 9:12, Steep slope: 9:12 and above.

Q3: Why is roof slope important for drainage?
A: Steeper slopes allow water to drain more quickly, reducing the risk of leaks, ponding water, and structural damage.

Q4: How does slope affect roofing materials?
A: Some materials like asphalt shingles require minimum slopes (typically 2:12 or 4:12), while metal roofing can work on very low slopes with proper sealing.

Q5: What is the minimum slope for proper drainage?
A: Generally, a minimum slope of 1/4:12 (2% slope) is recommended for adequate water drainage on most roofing systems.