1. What is Slope Ratio?

Slope ratio represents the relationship between vertical rise and horizontal run in roof construction. In Australian standards, it's typically expressed as a ratio (e.g., 1:4) showing how much the roof rises for every unit of horizontal distance.

2. How Does the Calculator Work?

The calculator uses the slope ratio formula:

Where:

• \( \text{rise} \) — Vertical change (measured in mm)
• \( \text{run} \) — Horizontal change (measured in meters)

Explanation: The calculator converts run from meters to millimeters to maintain consistent units, then calculates the ratio of rise to run.

3. Importance of Roof Slope Calculation

Details: Proper roof slope is crucial for water drainage, structural integrity, and compliance with Australian building standards. Different roofing materials require specific slope ratios for optimal performance.

4. Using the Calculator

Tips: Enter rise in millimeters and run in meters. Both values must be positive numbers. The result is a unitless ratio that represents the slope relationship.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical roof slope ratio in Australia?
A: Common residential roof slopes range from 1:4 to 1:12, depending on roofing material and regional building codes.

Q2: How do I convert slope ratio to degrees?
A: Use the formula: degrees = arctan(rise/run). Most calculators have a tangent function for this conversion.

Q3: Why are different units used for rise and run?
A: Australian building standards typically measure rise in millimeters and run in meters for practical construction measurements.

Q4: What's the minimum slope for different roofing materials?
A: Minimum slopes vary: corrugated iron (1:20), concrete tiles (1:22), metal tiles (1:20). Always check manufacturer specifications.

Q5: How does slope affect roof performance?
A: Steeper slopes improve water drainage but require more materials, while shallower slopes may need additional waterproofing measures.