Roof & Foundation Waterproofing Bitumen Membrane & Primer Estimator
Calculate SBS/APP torch-on bitumen membrane rolls (1x10m), asphalt primer drums, and vertical parapet upstand flashing with seam overlaps.
Total Waterproofing Rolls (10m² / roll)
Calculator Inputs
Total Waterproofing Rolls (10m² / roll)
Bitumen Primer Drums (18L / drum)
Total Gross Area with Overlaps
Vertical Upstand Surface Area
Flat Surface Area vs. Upstand Area Breakdown
Ensure mandatory 4-inch (10cm) side laps and 6-inch (15cm) end laps for 100% watertight torch-on applications.
All engineering calculations, structural estimates, and electrical sizing metrics are provided for preliminary estimation only. Always ensure compliance with relevant statutory building codes and occupational safety standards, verified by a certified professional engineer before practical implementation.
Calculation Methodology
Total Area = Flat Roof Area + Vertical Perimeter Upstands (0.3m height). Gross Membrane Area = Total Area * 1.15 Overlap Factor. Rolls = Ceil(Gross Area / 10m²).
Frequently Asked Questions
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