Home
Back
Slope Ratio Formula:
| From: | To: |
The slope ratio for flat roofs in Australia represents the relationship between vertical rise and horizontal run. It ensures proper water drainage while maintaining the appearance of a flat roof surface according to Australian building standards.
The calculator uses the slope ratio formula:
Where:
Explanation: The ratio indicates how many millimeters the roof rises for every meter of horizontal distance. Australian standards typically require minimum slopes of 1:100 to 1:80 for proper drainage.
Details: Correct roof slope is essential for effective water drainage, preventing ponding water, reducing leakage risks, and complying with Australian Building Codes. Insufficient slope can lead to structural damage and reduced roof lifespan.
Tips: Enter the vertical rise in millimeters and horizontal run in meters. Ensure measurements are accurate for reliable results. The calculator will provide both the decimal ratio and the standard ratio format (e.g., 1:100).
Q1: What is the minimum slope required for flat roofs in Australia?
A: Australian standards typically require a minimum slope of 1:100 (10mm rise per meter) for adequate drainage, though 1:80 is often recommended for better performance.
Q2: How do I measure rise and run accurately?
A: Use a spirit level and measuring tape. Measure vertical rise in millimeters from the lowest to highest point, and horizontal run in meters between these points.
Q3: Can this calculator be used for other types of roofs?
A: This calculator is specifically designed for flat roofs. Pitched roofs require different calculation methods and steeper slopes.
Q4: What if my calculated slope is below the minimum requirement?
A: If your slope ratio is below 1:100, you may need to adjust the roof structure or consider additional drainage solutions to meet Australian standards.
Q5: Are there different requirements for different roofing materials?
A: Yes, some roofing materials may have specific slope requirements. Always consult manufacturer specifications and local building codes for precise requirements.