Level of Difficulty: Intermediate Do-It-Yourselfer - Moderate
Completion Time: Week-end Project

Installing baseboard trim will frame your interior walls. Not only do baseboards add an essential finishing touch, by covering the joints between the walls and the floor they bring continuity to the flooring.

All it takes to install perfect baseboards, even on crooked walls, is a few household tools and the right style of baseboard trim for your home.

In this project, we propose that you install your baseboards with coped joints instead of mitre joints for the inside corners. The pieces will have a better fit as they expand and contract, so no gaps will develop.

TOOLS

  • Mitre saw, or Mitre box with saw
  • Mitre saw cutting supports, or Saw horses
  • Caulking gun
  • Tape measure
  • Hammer or Power nailing gun

  • Stud finder
  • Level
  • Coping saw
  • Round file
  • Square

MATERIALS

  • Baseboards
  • Wood glue
  • Wall panel adhesive
  • Paintable caulking
  • Finishing nails or Power brad Nailer
BEFORE ASSEMBLY
NOTES

MEASURING AND QUANTITIES
Taking measurements is an essential step in order to determine the quantity of mouldings required and the exact length of each piece.

Calculate the length of each wall using a tape measure. Add 12" to 24" for each wall to account for losses resulting from angle cuts. If there are obstructions that prevent you from installing mouldings (i.e. electrical baseboard, furniture, etc.), don’t forget to subtract them from the total length. If you are installing mouldings around a door or a window, determine the height and the width of each opening.

For aesthetic reasons, opt for long mouldings. For example, in the case of a 14' wall, use a 16' moulding rather than two 8' mouldings. You will reduce the number of joints and enhance the look of your mouldings.

CUTTING
The baseboards can be made from vinyl, painted wood or a medium density fiber (MDF). They can be 16’ long so it is important to set up supports at the height of the mitre saw to hold the mouldings in place. These could be sawhorses built up to height or adjustable supports with rollers.

Set up the mitre saw in a well-ventilated area outside the room to avoid dust.

Use a good-quality finishing blade with a minimum of 40 teeth, though 80 teeth is preferable since the more teeth a blade has, the cleaner the cut.

INSTALLATION
Before you start, allow the mouldings to acclimatize for 24 to 48 hours in the room where they will be installed.

You can paint or stain your mouldings in advance. You will simply need to touch them up a bit after, and cover the nail heads you’ve concealed with wood filler. This actually simplifies the job, because you won’t need to do any masking.

Mouldings can be fastened with finishing nails or a power nailer. Never use nails longer than 2" as you might hit a wire; 1 ½" nails are perfect for the job. For a cleaner, more professional job, use a brad power nailer. Pre-drill your nail holes so that mouldings do not split. Use a drill bit of a smaller size than the nails.

Lay flooring before installing baseboard to avoid unsightly voids and an uneven look.

On a long wall, shorter pieces can maintain the look of continuity by mitering the joints rather than having them butt together.

STEPS

1.1. Lean a baseboard on the wall keeping a set of 1/8" with the floor and mark the height with a line. This will prevent using the floor as a guiding line should it not be level. Measure the walls and mark the studs for nailing

1.2. Slash a level line all around the room marking the top of the baseboard.

1.3. Mark the location of the studs at the base of the walls. One way of doing this is to start the tape in the corner and put a mark every 16" on both walls from the corners. Use a stud finder for greater accuracy. In many cases, the studs can be found by looking at the bottom of the walls as most drywallers leave a narrow space above the floor.

1.4. Measure the base of each wall and write this measurement on a notepad. Start at the left of the entry door working toward the right.

MEASURE AND PREPARE THE INSTALLATION
2.1. Cut the first piece of baseboard 1/16 " longer than the wall. Cut both ends with square ends

2.2. Push the first piece into place and check the measurements.

2.3. Start the finishing nails in the moulding below the marks for the studs. There should be two 8d nails per stud, with the first being ¾" to 1" off the floor to hit the plate or bottom supporting structure of the wall. The second nail should be closer to the top of the baseboard. When using pine baseboards, it is best to predrill with a fine bit to prevent splitting. If using a power brad nailer, this is not required.

2.4. Nail the baseboard into place taking care to drive the top nail in to form a fit.

CUT AND INSTALL THE FIRST PIECE FOR WALL #1

3.1. Cut the second moulding 2" longer than needed with both ends at a 90o angle.

3.2. Mark the inside corner where the first and second mouldings will join and cut at a 450 angle with the short side of the mitre toward the face of the moulding.

3.3. Trace the edge of the mitre with a pen to make it more visible and cut the excess at a slight angle along the line with a coping saw. This is called a coped joint.

3.4. Adjust and fit the coped joint to the first moulding with a round file if needed. Square-cut the other ends so it butts into the corner.

3.5. Nail the baseboard into place taking care to drive the top nail in to form a fit.

3.6. Repeat the process for the other mouldings around the room that require inside corners cuts.

INSTALL THE OTHER MOULDINGS (INSIDE CUT)

If you need to join two mouldings along the same wall to complete the length, you can use either a 90o angle cut or a scarf joint. We recommend a scarf joint as it is less visible and provides a tighter joint.

4.1. Position both baseboards as they will be on the wall.

4.2. Locate the center of the stud that is closer to the end of the mouldings. Splices should always be located over a wall stud.

4.3. Cut both mouldings with a 45o angle so they overlap.

4.4. Position both baseboards in place. Measure the length needed for the second moulding to reach the wall and cut at a 90o angle.

4.5. Set both pieces in place and nail into the stud to form a fit. Completely nail in the baseboards.

JOIN TWO MOULDINGS

Outside corners are mitred at a 45o angle. Since corners are not always exactly 90o, you must test fit mitres.

5.1. Use a square to determine if the corner is a perfect 90o angle. If not, cut the end of two 1' length baseboards at a 45o angle to sample the corner angle and test the fit, making small adjustments. Take note of both angles. Sample mitres to determine the angle.

5.2. Position the baseboard in place and adjust the end to fit with the baseboard already installed on the wall.

5.3. Run a pencil line up the back of the piece where it overhangs the corner.

5.4. Set the mitre saw for 45º or to the angle determined during the test fit.

5.5. Cut the piece on the mitre saw along the pencil line with the finished side facing the fence of the saw.

5.6. Cut the second piece to length and nail.

CUT THE OUTSIDE CORNER

6.1. If the baseboards were previously painted, simply touch up where needed.

6.2. Fill small cracks in the corners and between the baseboard and wall with a paintable caulking. Wipe off excess with a damp cloth.

6.3. Lightly sand the surface with fine sandpaper.

6.4. Apply a primer and then paint.