Introduction #
This guide covers how to install shiplap on walls 14 feet and wider. Think great rooms, open-concept living areas, and commercial spaces, where the wall is longer than the boards you're using. The full step-by-step process is in our core guide: How to Install Shiplap, 0′ to 7′. Joint planning for mid-range walls is in How to Install Shiplap 2, 7′ to 14′. Read both guides first. This guide only covers what changes on a wall wider than 14 feet, where each course needs two or more butt joints (spots where the square-cut end of one board meets the next). Scale up, and you still install shiplap board by board. You just manage more of everything at once.
Wide walls bring problems that shorter walls don’t have. You’ll have more joints in each course. You may need scaffolding to reach the upper courses. Small mistakes show up more because the wall is so big, and you have more material to keep track of. The basic steps of how you install shiplap stay the same. You just have to plan more carefully and work more precisely. Crews who install shiplap on great room walls every week will tell you the same thing: the wood goes up fast, the joint plan is what takes the time.
What Changes When You Install Shiplap on Walls Over 14 Feet #
- Multiple joints per course. A 16-foot wall with 8-foot boards has two joints per course. A 20-foot wall may have three. The stagger (how you offset each joint from the joints in the course above and below it, so they don’t line up in a row) gets much harder to manage once you have more than one joint per course.
- Scaffolding replaces ladders. You can’t safely work 10 feet off the floor from a stepladder while holding a full-length board. Rolling scaffolding or a plank-and-bracket system is mandatory for the upper half of tall-wall installations.
- Board sourcing matters more. Longer boards (10′, 12′, or even 16′) dramatically reduce joint count. A 16-foot wall with 16-foot boards has zero joints - but those boards are heavier, harder to transport, and cost more. Weigh the tradeoff.
- Level drift is amplified. Over 14+ feet, even 1/16″ per course drift becomes noticeable. Check level every 2-3 courses with the longest level you have.
- Two-person job minimum. Solo installation is impractical at this scale. One person holds and positions while the other nails.
- Material staging is critical. Stack boards near the wall, sorted by length. Having to walk across a 20-foot room for every board wastes enormous time.
Additional Tools and Materials for Large-Scale Walls #
You’ll need everything in the core guide tool list and the 7-14 foot supplement, plus:
- Rolling scaffolding - adjustable height, at least 5 feet of platform width. Multi-level scaffold for walls over 12 feet tall.
- 6-foot or 8-foot level - a 4-foot level covers less than a third of the wall. Longer levels catch drift that short levels miss.
- Laser level (preferred) - projects a reference line across the full wall width. More accurate than any hand-held level at this scale.
- Board lifter or support T-bracket - for holding long boards in position while you nail. Commercial board lifters support one end hands-free.
- Extra material (15-20% overage) - more joints mean more cuts and more waste. Order accordingly.
Multi-Joint Stagger Planning for Wide Walls #
With two or more joints per course, you need to extend the stagger rules from the 7-14 foot guide to cover every joint position:
The Zone System #
Divide the wall into visual zones (roughly every 4-5 feet). Each course’s joints should land in different zones than the course above and below it. If Course 1 has joints in zones 2 and 4, Course 2 should have joints in zones 1 and 3 (or zone 3 only if using longer boards). No two vertically adjacent joints should share a zone.
Three-Board Layout #
For a wall requiring three boards per course (e.g., 20 feet with 8-foot boards): start the first course with a full board, then a full board, then the remainder. Start the second course with a half board, creating a brick-like stagger. Alternate the starting board length across courses so joints cascade across the wall rather than stacking.
Pro Tip: Map out joints for the first 6-8 courses on paper before cutting. Label each board with its position (Course 1, Board A / Course 1, Board B / etc.). Once the pattern is established, it repeats predictably for the remaining courses. This planning is worth 30 minutes because wide walls make bad stagger extremely obvious - it looks like a zipper running up the wall.
What’s Different Step-by-Step #
Follow the core guide for your chosen orientation. The modifications below apply primarily to horizontal installations (the most common for great rooms).
Step 1 (Layout) - Add Zone-Based Joint Planning #
Same layout process. In addition to course count and row balancing, create a full joint stagger map using the zone system described above. Mark zones on the wall with chalk. Verify every planned joint lands on a stud - on wide walls this occasionally means adjusting board lengths by a few inches to hit the nearest stud.
Steps 2-4 (Installation) - Scaffolding and Team Coordination #
Same installation process, but:
- Use scaffolding for any course you can’t comfortably reach from the floor. If you have to reach up with your arm stretched out to hold a board overhead, your nailing gets sloppy and you tire out fast.
- Work in pairs. One person holds the board in position while the other checks level and nails it. On boards 16 feet and longer, you may need a third support point too: a cleat, a board lifter, or another person.
- Check level every 2-3 courses with a laser level or the longest hand level available. Set the laser at the top edge of the course and verify across the full width.
- Tighten joints immediately. Push each board sideways, tight against its neighbor at the joint, before you nail it. On long runs, the board’s own weight can pull it away from the joint if you wait, so nail it while it’s still tight.
Step 5 (Finish) - Extra Attention at Joints #
More joints mean more nails to set below the surface and more end-grain cuts (cut ends of boards, where the wood grain is exposed) for the painter to finish. Budget extra time to close out a wide wall. A 20-foot wall may have 15-20 joints total, each with 4 nail locations to check. Flag the joint count for the painter ahead of time so he can plan for the extra fill and finish work.
Herringbone and Chevron on Wide Walls #
Angled patterns on walls over 14 feet are a lot harder than on smaller walls. Here’s what else to consider:
- Plywood backer seams. You’ll need 3-4 sheets side by side. Offset the seams and screw into every stud. Tape the seams with mesh tape so they don’t telegraph through the shiplap (show up as a ridge or line under the boards once they’re installed).
- Center line placement. On a 20-foot wall, consider whether the pattern’s center should align with the geometric center of the wall or the visual center of the room (they may differ due to furniture placement). Stand where the viewer will stand and assess.
- Waste factor increases to 35-45% for herringbone and 40-50% for chevron on wide walls. The edge trim cuts become progressively more wasteful as the pattern extends.
Material Planning for Wide Walls #
Walls over 14 feet require more careful material calculation than smaller projects. Start by measuring the total square footage, then add 15-20% for waste. The waste factor increases with wall width because more cuts generate more unusable offcuts.
Order all boards from a single lot or production run. On a wall this large, color and grain variations between lots become noticeable. If your supplier can’t provide enough from one lot, request boards from consecutive lots and shuffle them during installation to distribute any variation evenly across the wall.
For walls requiring butt joints, calculate board lengths against stud spacing before ordering. If your studs are on 16-inch centers and the wall is 18 feet, you’ll need boards that can be cut to land joints on studs while maintaining the stagger pattern. Pre-planning board lengths reduces waste and speeds up installation. Stage cut boards near the wall, labeled by course number, so you’re not measuring and cutting on the fly.
Quality Check - Additions for Walls Over 14 Feet #
Complete the full core guide quality checklist and the 7-14 foot checklist additions, then verify:
- Joint stagger follows zone system - no vertically adjacent joints in the same zone
- Level checked with laser or 6’+ level across full wall width - consistent within 1/16″ over any 8-foot span
- All boards are tight at joints - no gaps visible from 6 feet back
- Scaffolding marks or dents on the wall flagged for the painter, not filled or touched up on site
- For herringbone/chevron: plywood seams not telegraphing through shiplap surface
Troubleshooting - Very Wide Wall Issues #
Boards bowing between supports on long spans #
Long boards can develop a visible bow between nailing points, especially in humid conditions. Fix it by adding a nail in the middle of the span (the stretch between two nailing points) if there’s a stud there, or by running construction adhesive behind the board to hold it flat. If the bow is severe, the board may be warped. Replace it. When you’re working with boards over 10 feet, be extra picky about board straightness.
Courses drifting out of level across the full width #
Small errors show up more on wide walls. If you find your courses have drifted out of level, do NOT fix it all in one course. That creates a visible kink, a sharp bend in the line that catches the eye. Instead, spread the correction over 3-4 courses. Adjust the reveal a little at a time: slightly wider on the high side, slightly tighter on the low side. Spread out this way, the correction will be invisible.
Material color variation between boards #
Large orders often include boards from different production runs, with slightly different color or grain. Mix boards from different bundles as you install, so the differences spread out evenly across the wall instead of showing up as bands. If mixing the boards doesn’t fix it, flag the color variation before you get too far into the wall. Whether to pre-finish boards off site for a consistent color is the painter's call, not something we do in the field.
Helpful Resources #
The OSHA Scaffolding Standards provide safety guidelines for working at height - critical for projects on tall walls in great rooms.
A 20-foot wall and a 7-foot wall aren't really different jobs. It's the same discipline, just more of it: zone your joints, keep every one on a stud, work in pairs, and plan your joints on paper before you start cutting. Get that right and the wall reads as one clean, continuous surface from across the room, no matter how wide it is.
Related Guides #
- Core Guide: How to Install Shiplap, 0′ to 7′ - Complete installation process for all four orientations
- How to Install Shiplap 2, 7′ to 14′ - Joint management and stagger planning for mid-range walls
- How to Install Shiplap 4, Ceiling - Overhead installation techniques
- How to Install Shiplap on a 3-Sided Fireplace - Fireplace wraps with mitered corners
