EPDM Roof Calculator — Membrane, Adhesive & Trims
Calculate EPDM rubber membrane sizing with 150mm upstand allowance per BS 6229. Includes contact adhesive, perimeter trim and water check quantities.
How We Calculate This
This calculator sizes your EPDM membrane by adding upstand allowances to your roof dimensions, then calculates adhesive, trims and accessories.
The formula
Membrane size = (Roof length + 2 × Upstand) × (Roof width + 2 × Upstand)
Contact adhesive (L) = Membrane area ÷ Coverage rate (m\u00b2/L)
Perimeter trim = 2 × (Length + Width) + 10% extra
Frequently Asked Questions
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Last updated: March 2026
All calculations are estimates. Verify with your supplier.