Underlay seam length changes with strip direction.
Can two layouts use similar roll area but different seam-tape quantities?
Use the matching calculator
Use this decision sequence
- Choose a permitted laying direction from the supplied product and plan.
- Count parallel strips using usable width and the stated overlap model.
- Count the boundaries between those strips and multiply by their length.
- Keep perimeter tape, end joins and internal strip seams separate.
Keep the quantities distinct
| Quantity or assumption | How to use it |
|---|---|
| Strip count | Controls the number of internal seam lines. |
| Strip length | Controls length of each seam. |
| Perimeter | A different boundary quantity. |
Worked comparison
For an illustrative 4×3 m room and 1 m effective strip width, strips running 4 m long create three strip positions across 3 m and two internal seams, totaling 8 m. Turning strips to run 3 m long creates four positions and three internal seams, totaling 9 m. Neither value is the room’s 14 m perimeter.
Check before using the estimate
Direction and overlap are supplied; the calculation does not approve installation methods or product suitability.
All dimensions, product properties, prices and specifications in this example are illustrative arithmetic inputs. Use the values from your measured plan, selected product data sheet and supplier quote. This guide does not choose construction specifications or certify safety.
Calculation and scope checked 2026-10-04. Methods and scope.