Classic Wainscoting

As a decorative element, wainscoting adds warmth and character to a room-and it's fairly inexpensive to install, especially if you make your own. One of my favorite types of wainscoting is made from interlocking pieces of vertically laid tongue-and-groove pine. The illustrations show how all the parts of this particular style of wainscoting fit together and fasten to the wall. The vertical boards are fastened to the underlying wall frame, then trimmed with a combination of store-bought and shop-cut mouldings on top and a three-part baseboard trim on the bottom.

The Main Boards

Decorative tongue-and-groove lumber often comes with V-matched edges, where the visible outer corners of each board are heavily chamfered. Although this looks fine, I prefer to start with ordinary, square-cornered tongue-and-groove stock (shown here), about 3 1/2-inch to 5 1/2-inch wide, then use a table-mounted router to rout a 3/16-inch diameter bullnose profile on its front face, right next to each tongue. I first noticed this beautiful design approach on the original 1930s' oak wainscoting in my local post office, but have never seen it offered in any lumber outlet. It's a simple detail that deserves to be resurrected.

Anchoring the Wainscoting

First consider how you'll anchor your wainscoting to the wall. Vertical wall studs won't provide the continuous horizontal wood surfaces you'll need for solid nailing, so you'll have to make them. There are two ways to do this: Install either an inset nailing strip or a surface-mounted nailing strip. The inset approach is the preferred method, where the horizontal nailing members are set into notches cut in the walls' studs, if you can get at them. The advantage of an inset nailing strip is that it won't add to the thickness of the overall installation, but this is practical only if you're stripping an old wall right back to the bare frame, or building a new one.

The next best approach is to screw external nailing strips to the finished wall surface, directly into the underlying vertical studs. You could use 1 1/2-inch-wide strips of 3/4-inch thick pine or, if you want to reduce the thickness of the nailing strips, 1/2-thick plywood. Although you may be able to nail the bottom of your wainscoting into the horizontal bottom plate of the wall frame, a better option is to install a nailing strip near the floor, and one near the top of the wainscoting. I don't recommend gluing wainscoting directly to a wall-regardless of how strong a glue you use, the integrity of the installation will depend entirely on the bond between the paint or wallpaper and wall surface, rather than the bond between the glue and the wall.

Installation

After cutting to length, milling and finishing all the main wainscoting boards, mark pencil lines across each one where you'll be nailing through the boards to anchor them to the nailing strips underneath. There's no need to struggle with nailing diagonally through the tongues, because the cap moulding and baseboard will cover the nails.

Before you install the main vertical boards, draw a level line across the wall where you want the top ends of the boards. Fasten the end of each board in place with two spiral finishing nails that penetrate at least 3/4-inch into the underlying nailing strips. If you've chosen to use 1/2-inch plywood nailing strips, apply a small blob of glue under each board, in addition to the nails. The vertical boards that meet the corners of your room should be scribed to create a tight fit.

Cap Moulding

The cap I like to use is a two-part affair with a wide, 1/2-inch-thick, shop-cut bullnose on top (which, to my knowledge, is not available commercially) and a 1-inch factory-milled cove moulding directly beneath it. Besides looking good, this combination has several advantages. The shop-cut bullnose can be made as wide as necessary to cover the top of your wainscoting, and the cove moulding eases the visual transition between the bullnose and the wainscoting, masks any gaps between these parts, and covers the nail holes at the top of the boards. Use a bullnose router bit in a table-mounted router, or make two passes over a roundover bit, to make the bullnose. When you go to the lumberyard, you'll find that 3/4-inch cove moulding is common, but the larger 1-inch stock may have to be ordered. It's worth the wait for this application.

The Baseboard

The three-part baseboard is made up of a 1/2-inch or 3/4-inch-thick x 5 1/2-inch-wide piece of shop-cut stock, with a 1/2-inch-thick shop-made bullnose moulding on the top edge and a piece of 9/16'-inch X 3/4-inch quarter-round on the bottom face. The nice thing about the bullnose top cap is that it can be scribed and trimmed to eliminate gaps between the main part of the baseboard and the wainscoting.

Once you've prepared all of your stock, carefully sand all exposed surfaces (to remove mill marks, which will be especially noticeable if you apply stain). I strongly recommend that you finish all parts of your wainscoting before installation. Using 220-grit paper, sand between coats of urethane, varnish, lacquer, or whatever you're using to seal the wood. This is the single most important step in creating a smooth finish.

The nail holes in the cap moulding and baseboard will be exposed to view and should be filled. If you've stained and sealed your wainscoting, use matching wax filler sticks for this. Painted wainscoting can be filled with latex caulk or autobody filler, sanded, then touched up with more paint.