Flat Roof Slope Calculator
Calculate the slope of your flat roof. Determine pitch, slope percentage, and drainage requirements for proper water runoff.
Step 1: Roof Dimensions
Understanding Roof Slope
Flat roofs require a minimum slope for proper drainage. Typically, a slope of ¼ inch per foot (2% slope) is recommended. Too little slope can lead to ponding water and roof damage.
Step 2: Calculation Details
About Flat Roof Drainage
Proper drainage prevents water accumulation that can lead to leaks, structural damage, and reduced roof lifespan. Most building codes require at least 2% slope for flat roofs.
Roof Slope Results
Current Roof Slope
Building Code Slope Requirements
| Building Code | Minimum Slope | Recommended Slope | Your Roof | Status |
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Drainage Efficiency Analysis
Slope Calculation Formula
Slope = (Rise ÷ Run) × 100%
The roof slope is calculated by dividing the vertical rise by the horizontal run, then multiplying by 100 to get percentage. For flat roofs, slope is typically expressed as inches per foot or percentage.
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