Inputs
Units:
m
Horizontal plan length of the reinforced area.
m
Horizontal plan width of the reinforced area.
m
Embed or overlap beyond each length edge (each side).
m
Embed or overlap beyond each width edge (each side).
m
Allowance for trimming along length edges (each side).
m
Allowance for trimming along width edges (each side).
m
Dimension of one sheet along its length (roll direction).
m
Dimension of one sheet across its width (roll width).
m
Overlap between sheets end-to-end along the length.
m
Overlap between adjacent courses across the width.
Choose how sheets are laid relative to the site.
Adds alternate-row half-sheet starts for better seam distribution.
%
Allowance for offcuts during layout.
%
Allowance for damage, handling, site irregularities.
%
Additional spare sheets to keep on hand.
V:H
Optional: e.g.,
1:2. Applies along project length.
m
If using continuous rolls, estimate rolls required.
Results
Rows (length direction)
-
Columns (width direction)
-
Sheets before waste
-
Sheets total (final)
-
| Parameter | Value | Notes |
|---|
Example Data
These typical entries help you sanity‑check inputs. Adjust to match your product datasheets.
| Product Type | Sheet / Roll Width | Sheet Length / Roll Length | Typical Lap (Width) | Typical Lap (Length) |
|---|---|---|---|---|
| Biaxial base stabilization | 3.95 m | 6.0 m / 50 m | 0.3 m | 0.3 m |
| Uniaxial wall reinforcement | 2.5 m | 6.0 m / 75 m | 0.3 m | 0.5 m |
| High‑strength haul roads | 4.0 m | 8.0 m / 100 m | 0.4 m | 0.4 m |
Formula Used
We tile rectangular sheets with overlaps. Along an axis (A), the minimum sheets required to cover a required dimension R using sheet size S and lap L is:
N = 1 if R ≤ S; otherwise N = ⌈ (R - S) / (S - L) ⌉ + 1.
Required dimensions include allowances: Rlen = Length + 2×Anchoragelen + 2×Trimlen and Rwid = Width + 2×Anchoragewid + 2×Trimwid.
Optional slope factor along project length for ratio V:H uses √(1 + (V/H)²), applied to the length component.
Base sheets = rows × columns. If seams are staggered 50%, we approximate extra half‑sheet starts ≈ ⌈rows/2⌉ × 0.5. Final sheets include cut loss, general wastage, and spare percentages, rounded up.
How to Use
- Select units and enter project length and width in plan view.
- Enter anchorage and trim allowances for each side, if required.
- Set sheet dimensions and laps along both axes; choose orientation.
- Optionally provide slope ratio and roll length for continuous rolls.
- Set waste and spare percentages, then click Calculate.
- Review rows, columns, and totals; export CSV or PDF if needed.
FAQs
The effective coverage would be zero or negative. Reduce lap or use larger sheets; otherwise coverage cannot be computed.
It approximates extra half‑sheet starts for alternate rows. Complex perimeters or patterns may require adding a small cut‑loss percentage on top.
Use it when covering sloped faces where the sheet follows the slope, not for flat pads in plan view.
Yes. Provide the roll length. The tool assumes the sheet length dimension is cut along the roll length.
Consult local specifications and manufacturer guidance for lap lengths, splice details, and factors for damage, handling, or soft spots. Increase spare percentage accordingly.
At a Glance
- Overlaps both directions
- Anchorage & edge trim allowances
- Optional slope factor
- 50% seam stagger option
- Rolls estimation
- CSV & PDF exports
Tips
- Confirm lapping rules from specifications or supplier datasheets.
- Increase wastage for irregular boundaries and obstacles.
- Use staggered seams to avoid four‑corner intersections.
- Round up rolls to full units due to packaging.