Introduction #
Shiplap is a great wall treatment to learn. Builders first used it as siding on ships and barns. Each board has a tongue milled on one edge and a groove on the other, so it locks into the board below it. Sometimes we simply run flat square-edge boards with a consistent gap between them instead. Today shiplap makes great accent walls, feature walls, and full-room treatments in styles from modern farmhouse to contemporary minimalist.
Most people picture shiplap as horizontal boards, and that is exactly what this guide covers: smooth painted shiplap, run horizontal. Vertical, diagonal, herringbone, and chevron layouts each have their own guide, and prefinished material is covered there too.
You can install shiplap over existing drywall, or straight onto studs in new construction. The tongue-and-groove joint locks each board to the next, leaving a small shadow line, called a reveal, between rows. The basics: let the wood get used to the room’s temperature and humidity first, plan your layout, find your studs, and keep your spacing even all the way across.
Before You Begin #
Before you start, make sure these things are ready, and read through what you need to know below.
Prerequisites #
- Wall surface ready (drywall or exposed studs)
- Stud locations marked
- Material acclimated (left to adjust) to room humidity for 48 hours - stack boards flat with spacers between layers for air circulation
- Boards pre-finished if desired (painting or staining boards before you install them covers more of the board than painting a finished wall - once installed, you can’t easily get paint down into the reveals)
- Orientation chosen and layout drawn/planned on paper or the wall itself
What You Need To Know #
- Shiplap board “exposure” (visible width) is the board width minus the lap - typically 5.5″ or 7.25″ exposure for nominal 6″ and 8″ boards
- For horizontal: divide the wall height by the board exposure to get the number of courses (rows). If the top or bottom row comes out less than 2″, adjust your starting point, or rip boards (cut them narrower on a table saw) to equalize
- Nail boards into studs. Where a stud cannot be hit, glue the board rather than relying on a nail into drywall alone
Tools Required #
Power Tools #
- Miter saw (for crosscutting boards to length)
- 18-gauge brad nailer
- Table saw (for ripping edge boards to width)
- Stud finder
- Jigsaw or oscillating multi-tool (for outlet/switch cutouts)
Hand Tools #
- Tape measure
- Pencil
- Level (6-foot, for drawing stud lines)
- Chalk line
- Utility knife
- Block plane (for fine-fitting edge boards)
Supplies #
- 18-gauge brad nails (2″, long enough to reach the studs through drywall)
- Spacers (nickels, 1/8″ shims - thin strips that hold a consistent gap - or purpose-made spacers for consistent reveals)
- Construction adhesive (not needed for horizontal when you can nail into studs; use it only where you cannot hit a stud and the board would otherwise tack into drywall alone)
Materials #
- Shiplap boards (tongue-and-groove, or square-edge with a consistent gap). Smooth painted shiplap is almost always MDF: it does not split, and it fills and sands easily.
How to Install Shiplap Horizontally (Classic Method) #
Horizontal is the easiest way to install shiplap. Boards run left to right across the wall, lapping over each other as you work from the bottom up. Start here if this is your first shiplap wall.
Step 1: Prepare the Wall and Plan Layout #
Find and mark all stud locations (16″ or 24″ on center). Measure the wall height. Divide it by your board exposure to get the number of courses. Check whether the top or bottom row will end up as a thin sliver. If the math leaves you with a row less than 2″ at top or bottom, split the difference - rip both the first and last rows so they’re equal and look planned. Snap a level chalk line for the first course.
Pro Tip: Mark stud locations on the ceiling and floor with painter’s tape arrows pointing down/up. This way you can see where to nail even after the studs are covered by installed boards.
Step 2: Install the First Course #
This is the MOST IMPORTANT board in the whole wall. Every course above it follows its line, so it must be perfectly level. Start at the bottom, tongue side up, so the groove side of the next board fits down over it. Run a level across the full length of the board. If the wall is uneven, shim behind the board (slide a thin strip of wood behind it to fill the gap) to hold it level. Nail into every stud with 18-gauge brads - two nails per stud, one near the top edge and one near the bottom. We almost always face nail shiplap. On smooth painted shiplap that is fine, the painters fill and sand every nail hole. Just watch that no shiny fastener heads sit proud to catch the light.
Pro Tip: If the floor isn’t level (and it probably isn’t), DO NOT follow the floor line. Follow your LEVEL line. A level board with a small gap at the floor (hidden by baseboard) looks infinitely better than a crooked board that follows an uneven floor.
Step 3: Build Up Course by Course #
Place the next board on top with the lap joint engaged. Use a nickel or spacer to hold a consistent reveal between boards. Nail into every stud. Check for level every 4-5 rows. If boards have drifted, make small adjustments spread over 2-3 rows rather than one big correction.
Step 4: Handle Outlets and Switches #
Mark outlet and switch locations on the board. Measure from the board below AND from the nearest wall end. Cut openings with a jigsaw or oscillating tool. Cut slightly oversized - the outlet cover plate will hide the edge. Always turn off power at the breaker before working around electrical.
Pro Tip: Mark on the BACK of the board and cut from the back to avoid tear-out on the visible face. Also consider that outlet boxes may need extender rings since the shiplap adds 3/4″ of depth to the wall surface.
Step 5: Install the Top Row and Finish #
The top row likely needs to be ripped to fit. Measure the remaining gap at multiple points across the wall (the gap may vary). Rip on a table saw for a clean, straight edge. We do not cap the top edge with crown molding or ceiling trim. Scribe the last board tight to the ceiling instead: take measurements at several points across the wall, rip the back edge off the groove so the board drops straight in, and bevel that top edge back about 10 degrees so the face sits tight to the ceiling. Set every nail below the surface and hand the wall off to the painter for filling, sealing the perimeter, and finish work.
Close-Out After You Install Shiplap #
Regardless of the pattern you chose, close it out the same way:
- Set every nail below the surface, nothing proud to the touch. Run a hand along every course to catch what your eye misses.
- Wipe any glue squeeze-out while it is still wet, before it skins over and has to be scraped.
- Sweep up - cutoffs collected, dust off the floor and sill.
- Install trim - baseboard at the bottom, crown or flat stock at the ceiling, and edge trim at side walls where the shiplap terminates.
- Install outlet/switch plate covers once the painter is done. Use oversized covers if the cutouts aren’t perfectly clean.
Filling the nail holes, sealing the perimeter where shiplap meets the walls, ceiling, and baseboard, and any finish touch-up all belong to the painter. He fills and coats the whole wall in one pass with one set of materials. Holes filled ahead of him tend to look different once he applies the finish. What he needs from us: every nail set below the surface, glue cleaned off the joints, trim installed, and a swept floor.
Quality Check After You Install Shiplap #
- Reveals consistent throughout (same spacing between every board)
- Boards tight to each other at lap joints
- Every nail set below the surface, nothing proud to the touch
- Glue cleaned off every joint, no dried squeeze-out left on the face
- No warped or bowed boards visible
- Outlet/switch cutouts clean and covered by plates
- All courses level across full length
- Top and bottom rows are equal width (or close to it)
Troubleshooting #
Even when working carefully, problems can arise. Here are the most common issues and how to fix them.
Boards are bowing/not lying flat #
The wall surface is uneven. Add shims behind the board at low spots, or screw through the board into studs to pull it tight (fill the screw hole).
Reveals getting wider or narrower #
Boards may vary in width from piece to piece. Re-establish level every 4-5 rows and adjust spacing to compensate. Small adjustments spread across several rows are invisible - one large correction on a single row is obvious.
Board splits when nailing near the end #
Drill a pilot hole (a small starter hole that keeps the wood from splitting) before nailing within 2″ of any board end. Or use a shorter brad nail instead. This happens most often in hardwood and dry material.
Last row is a thin sliver #
This happens without planning the layout first. Remove the bottom course, rip it thinner, and redistribute the height difference so both top and bottom rows look intentional. This is why layout planning before cutting is non-negotiable.
