1. What Is Flat Roof Pitch?

Flat roof pitch refers to the slight slope or incline of a flat roof, typically measured as a ratio of vertical rise to horizontal run (m/m) or in degrees. Even "flat" roofs require a minimum pitch for proper water drainage.

2. How Does The Calculator Work?

The calculator uses the basic pitch formula:

Where:

• \( Rise \) — Vertical height difference (meters)
• \( Run \) — Horizontal distance (meters)

Minimum Requirements: Flat roofs typically require a minimum pitch of 0.0087 m/m (0.5°) for proper drainage.

3. Importance Of Proper Roof Pitch

Details: Proper roof pitch is essential for effective water drainage, preventing ponding water, extending roof lifespan, and maintaining structural integrity.

4. Using The Calculator

Tips: Enter the vertical rise and horizontal run in meters. Both values must be positive numbers. The calculator will provide results in both m/m ratio and degrees.

5. Frequently Asked Questions (FAQ)

Q1: What is the minimum pitch for a flat roof?
A: The minimum recommended pitch is 0.0087 m/m or 0.5 degrees to ensure proper water drainage.

Q2: How is pitch different from slope?
A: In roofing terms, pitch and slope are often used interchangeably, though pitch is typically expressed as a ratio while slope can be expressed as a ratio, percentage, or angle.

Q3: Can a roof be completely flat?
A: No, even "flat" roofs require some pitch for drainage. Completely flat roofs would allow water to pool, leading to leaks and structural damage.

Q4: How do I measure rise and run?
A: Rise is the vertical height difference between two points, run is the horizontal distance between those same points. Use a level and measuring tape for accuracy.

Q5: What materials work best for low-pitch roofs?
A: Built-up roofing (BUR), modified bitumen, EPDM rubber, and PVC membranes are commonly used for low-pitch and flat roof applications.