Worked layout
Vertical shiplap around Window 1: coverage, blanks and stock
Example measurements
- Wall
- 120 × 96 in
- Window 1 outside trim
- 36 × 42 in
- Window left / bottom
- 42 / 30 in
- Clearance, all sides
- 0 in
- Actual width / installed coverage
- 6 / 5½ in
- Thickness / raw stock
- ¾ in / 10 ft
- Kerf / trim at each end
- ⅛ / ¼ in
- Reserve / sale unit
- 10% extra stock / single boards
Layout result
- Vertical columns
- 22
- Final installed coverage
- 4 1/2 in
- Manufacturing blanks
- 28
- Net installed area
- 69.50 sq ft
Stock estimate for these measurements
21 boards to buy: 19 allocated to the blanks + 2 reserve + 0 for pack rounding. Each board is 10 ft long.
This is an illustrative material specification, not a product recommendation. No seams are needed in these vertical runs. The stock estimate includes the stated kerf, end trims and reserve; it does not certify the physical notch or retained lap.
| Board columns | Blank length × actual width | Quantity | Coverage at the opening |
|---|---|---|---|
| C1–C7, C16–C22 | 8 ft × 6 in | 14 | Rectangular coverage; check laps and any final edge trim |
| C8, C15 | 8 ft × 6 in | 2 | Partial-width intersection; retain a full-length blank for product-specific notching |
| C9–C14 | 2 ft 6 in × 6 in | 6 | Rectangular coverage; check laps and any final edge trim |
| C9–C14 | 2 ft × 6 in | 6 | Rectangular coverage; check laps and any final edge trim |
Before cutting: Confirm the product's retained lap and edge finishing before cutting this board. The drawing shows installed coverage, not a cutting template; the blank retains the full actual board width.
Compare on the same wall
Only the named layout setting changes. Wall measurements stay the same.
horizontal courses
5 1/2 in installed coverage · 25 pieces on Living-room wall
Stock estimate blocked: No available stock fits this complete blank. Choose longer stock or define a supported seam; the piece has not been split.
Try this variation →vertical courses
5 1/2 in installed coverage · 28 pieces on Living-room wall
Stock estimate: 21 boards to buy, including the specified reserve. Review the product edge checks before cutting.
Try this variation →Count coverage bands, then check the boards behind them
Read the worked example as three related answers: how many courses or columns cover the wall, how much of the final face is visible, and what stock is needed to make the pieces. One coverage band does not always equal one purchased board. It may be too long for the stock, interrupted by a window, or cut from part of a larger blank.
The example wall is 120 × 96 in. Its vertical boards have a 6 in physical width and 5½ in installed coverage. Window 1 is a 36 × 42 in casing boundary with zero clearance; its lower-left corner is 42 in from wall-left zero and 30 in above the floor. Keep those inputs in view while following the pieces beside the opening. Some need notched blanks even though the window removes visible wall area.
A window removes coverage, not necessarily a whole blank
Trace a board beside Window 1 from bottom to top. Where only part of its width crosses the opening, material can remain along the side while the middle needs a notch. Removing the whole band would leave wall uncovered. Likewise, pieces above and below the opening retain their own lengths; window square footage alone cannot describe them.
The example’s coverage drawing and blank schedule deliberately serve different purposes. The drawing shows the remaining wall region; the schedule retains the material required to form it. The 6 in physical board is wider than its 5½ in installed coverage, so its lap detail needs product review. Cut-schedule and installation output are blocked for this example: the coverage outline is not a physical notch-cutting template. Retain the blank allowance in the estimate, and deduct overlapping opening areas only once.
Match every required blank to usable stock
The purchasing example uses a ¾ in thick demonstration profile sold as individual 10 ft boards. It allows a ⅛ in saw kerf and ¼ in trimming at each stock end. These are stated scenario inputs, not a recommended commercial product. Read the calculated blank schedule and purchase total with those settings in mind; nominal board length is reduced by the end preparation needed before making finished pieces.
This is why a nominal eight-foot board cannot automatically supply an eight-foot finished run after trimming. If a required run exceeds usable stock, compare a longer available board or explicitly specify a supported seam arrangement. The product’s support and joint instructions govern where a seam can be built. A footage total cannot approve an arbitrary butt joint.
Add reserve after the required pieces fit
The example applies 10% extra stock after packing the required blanks. That is spare purchased material, separate from kerf, end trimming, and offcuts. It does not change the board shapes or enlarge the window deduction. Replace the demonstration reserve with an allowance appropriate to the selected product and project.
To compare purchase options, keep the installed pieces fixed and change a relevant buying condition: available stock length or reserve, for example. Check the longest blank as well as the final board count. If the product comes in boxes, reconcile the demand with the lengths, quantities, and product variants actually included in each pack.
Recheck the order if you rotate the layout
Use the orientation comparison above to rotate the same wall and window while retaining the material settings. Review the changed course or column count, final visible face, run lengths, and opening cuts. Read any stock-length blocker before ordering. The separate horizontal and vertical templates show uninterrupted walls; use those only when that simpler wall matches your project.
Metrie’s linked instructions address different starting-board alignment for horizontal and vertical installations and discuss cutting openings in its product. Check the corresponding instructions for the board you select to settle the starting edge, support, and joint positions. Until those details are resolved, the drawing explains coverage and the retained blank demand, not a ready-to-cut installation around the window.
Questions about this layout
Can I subtract the window’s square footage?
Use net area to check visible coverage, but keep the remaining piece shapes in the stock estimate. Notched blanks and the required lengths above, below, and beside the opening cannot be recovered from an area total alone.
Why can a window leave a full-width blank in the list?
A board may need a notch while retaining material along the opening’s side. It still has to be cut from a large enough blank. In this example, the lap detail also needs review, so the coverage outline is not a physical notch-cutting template.
Is the final partial face extra waste?
The visible partial face is required coverage. The remainder removed from its blank is a separate material question. Check whether that remainder is usable elsewhere before counting it as either reusable stock or waste.
Sources and assumptions
- Metrie: Prefinished Matte ShiplapProduct-specific dimensions, coverage, starting-board alignment, opening cuts, and orientation guidance. Apply the instructions for the product you actually buy.
- TrimLayout Calculation MethodsDefinitions of clear gaps, measurement references, finished pieces, and material allowances used in these examples.
- NIST: SI Units — LengthUnit relationships for converting measured lengths; this source does not prescribe decorative proportions.