Modified Bitumen Calculator
Calculate your modified bitumen roofing material requirements with our comprehensive calculator. Estimate rolls needed based on roof area, roll dimensions, and overlap requirements.
Step 1: Roof Details
Understanding Roof Complexity
Simple roofs have minimal penetrations and straight lines. Complex roofs have many penetrations, valleys, and irregular shapes that require more material waste during installation.
Step 2: Roll Specifications
Standard Roll Sizes
Standard modified bitumen rolls are typically 3.28ft (1m) wide and 65.6ft (20m) long, covering approximately 215 sqft (20 sqm) per roll. Always check manufacturer specifications.
Material Calculation Results
Total Rolls Required
Roof Type Comparison
| Roof Type | Waste Factor | Rolls Required | Total Area Covered |
|---|
Material Breakdown
Calculation Formula
Rolls = (Roof Area × Waste Factor) ÷ Roll Coverage
To calculate modified bitumen rolls needed: Multiply roof area by waste factor (1 + waste percentage), then divide by the coverage area of one roll. Always round up to the nearest whole roll.
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