Membrane Penetration Patch Blank calculator.
Count square patch blanks that fit a sheet around identical measured penetrations, without reusing cut-out centres.
Your inputs
Use measurements from your plan and properties from your chosen product. Any prefilled values are illustrative.
A clear estimate starts here.
Enter your dimensions and product details to see the quantity and purchase breakdown.
Formula and assumptions
How this calculation works.
Count square patch blanks that fit a sheet around identical measured penetrations, without reusing cut-out centres. Blank side = diameter + 2 × supplied margin; blanks/sheet = floor(sheet width / side) × floor(sheet length / side).
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Measured penetration diameter
- 100 mm
- Specified patch margin beyond penetration
- 100 mm
- Identical patches
- 20
- Stock sheet width
- 1 m
- Stock sheet length
- 1 m
Patch sheets to purchase: 3 sheets
Uses square patch blanks with a user-specified margin. Removed centres and edge offcuts are not reused; no sealing detail is designed.
Before you purchase
Use dimensions from your plan and properties from your chosen product. Any design spacing, section or fixing pattern must already be specified.
All product dimensions, coverage, density, allowances and joining rules must come from your supplied plan or selected product. No building-code values are inserted.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-05. Calculation and review policy.