Installing baseboard

MATERIALS: Molding, finishing nails, caulk

TOOLS: Tape measure, hand or power miter saw, hammer, nail set, coping saw, chop saw, rat-tail file, sliding T-bevel

Installing baseboard requires only two things: a sharp saw and a sharp mind. The joint used to connect two pieces of baseboard is unlike any other joint in woodworking. It’s called a cope joint because it’s cut with a coping saw; one board is cut to nest into the profile of another. A simple miter joint for molding work is inadequate. While the joint looks great when installed, changes in the weather cause the wood to expand and contract. Gaps develop and the joint looks sloppy and unfinished.

The cope joint solves this problem. With the two pieces fitting together like jigsaw puzzle pieces, they expand and contract in unison, leaving no gaps. Installing coped baseboard usually begins on the wall opposite the door. The baseboard runs from wall to wall, with each end cut square. The pieces that meet the first piece are coped to fit it, and then cut square on the other end. On the wall with the door in it, the baseboard is coped in the corner and cut square where it meets the door trim.

Cut the molding a bit longer than the wall it goes against, and then nail it flat to the wall. The extra length ensures a tight joint and holds the molding in place. If you’re putting in a lot of baseboard, consider renting an air compressor and an nail gun that drives finishing nails. They will make the job easier and faster.

A cope joint hides wood expansion and contraction by nesting pieces of molding in the corner. Baseboard molding comes in several basic profiles and varying heights.

BASEBOARD OPTIONS - Do your research when it comes to buying baseboard. You’ll find three broad types to choose from, and making the wrong choice will either cost you money or cause you no end of problems.

• Stainable baseboard is the most expensive and best grade. It’s allowed to have a few imperfections such as small pitch pockets or checks, for example, but the size and amount of defects are limited. However, most molding is made of pine and it turns blotchy when you apply liquid stains. Use a gel stain for a uniform color—it’s also thicker and the wood absorbs it more evenly.

• Paintable molding is allowed to have a few more blemishes—the kind a coat of stain will show but a coat of good paint will hide. It can be made of several shorter pieces joined together by finger joints and is less expensive than stainable grade. You can buy preprimed molding, but it’s best to prime it anyway. The factory-applied primer will have aged and lost some of its characteristics by the time you purchase the board.

• Medium Density Fiberboard (MDF) is a manufactured board made of ground wood fibers glued together. It has no grain; the surface is smooth and, as a result, it takes paint beautifully. It also comes preprimed but benefits from a coat of primer. Sand with a fine-grit paper to smooth, but less aggressively than you would sand wood, as you can raise more grain than you knockdown.

1 LAY OUT THE CUT IN PENCIL, USING A SQUARE TO TRANSFER THE MARK TO THE TOP OF THE MOLDING. Put the molding in the chop saw, positioning it so that the cut will result in a board that is too long.

2 START THE CUT, BUT GO NO DEEPER THAN 1/8 INCH INTO THE MOLDING. While holding the molding, slide it along the fence until the saw cut just touches the pencil line.

3 EASE THE SAW INTO THE MOLDING AND FINISH THE CUT. The slower you lower the saw, the smoother it will cut and the better the joint will be.

4 BEGIN ON THE WALL OPPOSITE THE DOOR. Cut a piece Vu inch longer than the wall. Put the ends up against the corners, positioning the molding about 1/16 inch above the floor to avoid any irregularities. The piece will bow away from the wall slightly. Push on it to put it into place.

5 NAIL THE BASEBOARD IN PLACE. Drive nails through the bottom of the baseboard into the 2x4 plate that runs along the floor inside the wall. Drive nails through the top into the studs. If the wood is difficult to nail, predrill for the nails. Clip the head off a finishing nail, put it in your drill, and use it like a regular bit.

6 COPE THE BASEBOARD THAT MEETS THE BOARD YOU’VE JUST INSTALLED. Begin with a piece longer than you'll need. Cut a miter on the end you'll be coping. Trace along the edge of the miter with a pencil to outline the profile.

7 CUT ALONG THE PENCIL LINE WITH A COPING SAW. Angle the saw slightly to create a pointed edge that will fit the other side of the joint snugly. For a smooth cut, use the finest blade you can get and let the saw do the work. Trying to push the saw forward will cause it to jam in the wood.

8 EVEN THE PROS NEED TO FINE-TUNE A COPED JOINT. Test-fit your joint and make any necessary corrections by filing with a rat-tail file. Fill in any small mistakes with caulk once the molding is in place. If you make a big mistake, cut off the joint and try again. Stain and finish the baseboard before installation.

GETTING A TIGHT FIT - Many carpenters, including the pros, wish there was a tool called a "board stretcher," which would magically add length to a piece that was mistakenly cut too short. Well, board stretchers don't exist so experienced carpenters always add about 1/16 inch to the overall length of the wall. Cut the molding to this length by making a square cut at the end opposite the coped joint. Spring the molding in place, and nail as before. For a neater job, some carpenters cut off the tip of the coped piece where it overlaps the top of the mating piece.

Rat-tail files are inexpensive and work well for fine-tuning any mitered or coped cut before installation.

9 CUT THE MOLDING FOR THE REMAINING WALLS THE SAME WAY: Cope, measure, cut, and nail. On the fourth wall—which has the door in it—cope the molding in the corners, and cut butt joints where it meets the door trim.

10 CUT QUARTER ROUND (ALSO CALLED SHOE MOLD) TO FIT ALONG THE BASEBOARD ON THE WALL OPPOSITE THE DOOR. Like the piece it sits against, it should be 1/16 inch longer than the wall, and both ends should be butt joints. Nail the quarter round to the floor so it won't lift it up and down with the expansion and contraction of the baseboard.

11 INSTALL THE REST OF THE QUARTER ROUND, FOLLOWING THE PATTERN OF THE BASEBOARD. Cope the ends that meet the first wall. Cut butt joints in the end of the molding that meets the wall with the door in it. Cut a butt joint where the molding meets the door trim; cope the other end.

12 OUTSIDE CORNERS ARE MITERED. Start by cutting a couple of sample miters to see how the corners meet. A gap means that the corner isn't a true 90 degrees. If the gap is wider at the wall, the corner is greater than 90 degrees; if it is wider at the point of the miter, the corner is less than 90 degrees.

13 RECUT THE SAMPLES TO CLOSE THE GAPS. To lay out the cut, draw a line parallel to each wall by putting your framing square against the wall and tracing along it lightly with a pencil. Make sure the lines intersect.

14 DETERMINE THE ANGLE OF THE LINE WITH A SLIDING T-BEVEL; set the miter saw to this angle. Cut a trial joint, test the fit, and correct as necessary. Make small angle adjustments without moving the saw itself by slipping a playing card or a bit of sawdust between the molding and the fence of the miter saw.

Built-Up Moldings

1 SOME BASEBOARDS ARE MADE UP OF SEVERAL MOLDINGS. A typical example begins by cutting and nailing a 1x4 or a 1x6 to the wall. All the joints are butt joints. Sometimes you'll need to nail thinner strips to the wall first so that the cap molding, installed in the next step, will seat properly.

2 NAIL ON A CAP MOLD, cutting and coping the joints as you would for regular baseboard.

3 INSTALL QUARTER-ROUND MOLDING. Cope, miter, and nail it to the wall as you would for any other baseboard. Drilling pilot holes will make nailing more accurate and easier to do. If you're installing a lot of molding, renting an air compressor and a nail gun will save you time and effort.

Log in to comment