In Part 1, we covered the tools and techniques to set up shop and make decisions for dialed-in shiplap. Here in Part 2, we’ll still hit the tools I use for tight finishes, but the focus shifts to layout and intersections with other elements on the wall: base, case, and crown. So, the “tools” I reach for first are questions I will need answered: Is the shiplap thicker than the casings? How do I transition to the base molding? Do I want the shiplap to butt into the base or lap over it?

The answers will vary based on context; it might not be worth tearing out the base in a reno. And it might be worth adding a square stock base when you’re starting new. There’s no rule of thumb. Addressing the questions ahead of time is the most important tool I have, not necessarily what the answer is.

If you want to lap over existing trim, as if the shiplap was the wall sheeting, then it’s easy. To do this properly, you may have to treat the whole wall and add extension jambs to doors and windows. (Gary Katz runs down extension jambs here). If you’re running it as a wainscoting, you will have to butt it to the existing casing. If the trim is too small, you can replace it or add a back band. Making a back band is as easy as milling up a block of 5/4 with a rabbet and some round overs, or buying something pre-made. As mentioned in Part 1, the rabbet is easily made with a table saw (check out the Skilsaw wormdrive table saw review here) and a sander to remove the saw marks.

The first step to installing shiplap is to figure out the intersections with existing or to-be-installed trim elements—base, case, and crown. While how I address it varies, answering those questions early in the process is key.
The first step to installing shiplap is to figure out the intersections with existing or to-be-installed trim elements—base, case, and crown. While how I address it varies, answering those questions early in the process is key.
When using shiplap as a wainscoting, make sure to consider device heights and how the switchplates will intersect with the shiplap or whatever top cap assembly you use.
When using shiplap as a wainscoting, make sure to consider device heights and how the switchplates will intersect with the shiplap or whatever top cap assembly you use.
To create a slight reveal between the shiplap and the base I like best (1x6), I pack it out with Ram Board. Works like a charm.
To create a slight reveal between the shiplap and the base I like best (1x6), I pack it out with Ram Board. Works like a charm.

Base tends to be slightly harder, but there are some easy options. First, just putting a thinner base over the shiplap works. But you have to make sure it’s behind the door casing to avoid having it stick past—or that you have a return or back bevel that everybody likes. The best way I’ve found to create reveals around the base without sticking it proud of the door casing is to pack out the wall so my base protrudes just enough to clear the shiplap and give me the shadow line I need. My favorite base is a 1x6 that I pack out 1/8 inch. Packed out an 1/8 inch, it’s still behind the casing and proud of the shiplap, and it blends nicely with the casing. To achieve the packout, I use Ram Board (check out this story in JLC on demo-proofing a jobsite) or Thermo-Ply to shim it, because 1/8-inch-thick material isn’t really a thing. If your casing allows, you can use lauan, which is around 3/16 inch.

Once you have termination points laid out and the type (dado, butt, return) laid out, it’s a matter of nailing it to the wall. Almost. First, avoid slivers.

You don’t want to start running the shiplap and end up with a sliver at the top, or worse, a tapered sliver. So, a little math goes a long way. I love the Construction Master Pro app on my phone. I use it on almost every project. Just measure the wall height in a few places, measure the shiplap reveal, then divide to see how the pieces land. You can divide the border piece in half—like tile or a suspended ceiling with even pieces on each end—or put the whole border piece on one end. Sometimes it looks better to have the border piece at the bottom, sometimes at the top. It’s personal preference.

Once I figure out the width of the bottom piece, I like to run my laser along the room and make horizontal reference marks. Then you can get that bottom piece level—or parallel with the ceiling, whichever works better—and nailed on. I use an 18-gauge brad nailer for this and for most of my trim. I face-nail the bottom, then into the tongue. On nickel gap, you have to nail a little higher in the tongue so you don’t see the nails in the gap. On tight gap, you have to face-nail it, as there is no tongue. Using tight gap, you could run from the top down, but usually I run it bottom up and we put a trim piece to close the gap at the top, usually a crown or flat stop.

Whether you are working on a fireplace or full wall, slivers must be addressed before installation. I use the Construction Master Pro app on my phone to figure out where the skinny piece will be and how big it is, and that determines how I address it.
Whether you are working on a fireplace or full wall, slivers must be addressed before installation. I use the Construction Master Pro app on my phone to figure out where the skinny piece will be and how big it is, and that determines how I address it.

V-Joint Shiplap

V-joint, or 45-degree shiplap, is a little trickier. It takes more patience, lay out, and time. Measure some reference lines off the ceiling as square using the 3,4,5 method or using a laser level. You will need both vertical and horizontal lines to reference to find your 45-degree lines to start off. Once you have your reference line, you can measure back using a framing square and then install your first piece. Keep checking along the way so both sides of the V descend the wall at the same rate.

A laser is my friend for the V because the vertical line is so important. On a small wall, you only have to center your vertical line. On a long wall, you may have multiple Vs and those verticals need to be laid out carefully by deciding where those V points will be. After shooting the laser, I snap those lines. Next, I shoot a few horizontal lines as a reference. It doesn’t matter where, just as long as the shiplap tips are the same measurement from the line. Then just keep going from there, measuring to make sure it’s staying true, and you will have a good-looking wall.

Photos by Chris Klee