Install baseboards

Baseboard trim not only covers the gap between the walls and the floor but also adds character and dimension to a room and provides an elegant finishing touch.

For this project, we suggest you assemble the mouldings using 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.
1

Measure and mark the installation height

  • 1.1 - Calculate the length of each wall and note down the measurements.
  • 1.2 - Add 12" to 24" for each wall to account for losses resulting from angle cuts.
  • 1.3 - Subtract from the measurement any elements that do not need moulding, such as electrical baseboards.
  • 1.4 - Opt for pieces longer than the wall to avoid joints. For example, in the case of a 14' wall, use a piece of 16' moulding rather than two 8' lengths.
  • 1.5 - Lean a baseboard against the wall, 1/8" above the floor, and mark this height with a line. This will prevent using the floor as a guiding line, as it is not always level.
  • 1.6 - Draw a level line all around the room to mark the position of the top of the baseboard.
  • 1.7 - Identify the location of the studs at the base of the walls. Either do this with a measuring tape, starting in one corner and putting a mark every 16", or use a stud finder for greater accuracy. Start from the left of the door working toward the right.
  • 1.8 - Measure the base of each wall and note the cutting angle.
Moulding calculator
2

Cut and install the first piece along the wall

  • 2.1 - Cut the first length of baseboard 1/16 " longer than the wall. Make a square cut at both ends.
  • 2.2 - Lean the piece against the wall and check the measurements. Adjust as needed.
  • 2.3 - Drive in a first nail, ¾" to 1" off the floor, into the plate or bottom supporting structure of the wall.
  • 2.4 - Drive in a second nail closer to the top of the baseboard.
  • 2.5 - Properly drive in the top nail to ensure the baseboard fits snugly against the wall.

Pro Tip

When using pine baseboards, it is best to drill the nail holes in advance, to prevent the wood from splitting. Use a drill bit slightly finer than the nail diameter. This step is not required if you are using a brad power nailer.
Cutting a coped joint in the baseboard
3

Install the other mouldings with inside cuts

  • 3.1 - Cut the second moulding 2" longer than needed with a square cut at both ends.
  • 3.2 - Mark the inside corner where the first and second mouldings will join.
  • 3.3 - Cut at a 45° angle with the short side of the mitre toward the face of the moulding.
  • 3.4 - Trace the edge of the mitre with a pen to make it more visible.
  • 3.5 - Cut the excess at a slight angle along the line with a coping saw. This is called a coped joint.
  • 3.6 - Adjust and fit the coped joint to the first moulding by shaping the surface with a round file if needed.
  • 3.7 - Square-cut the other end so it butts into the corner.
  • 3.8 - Nail the baseboard into place taking care to drive the top nail in well to form a fit.
  • 3.9 - Repeat the process for the other mouldings around the room that require inside corner cuts.

Pro Tip

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.
4

Join two mouldings with a scarf joint

  • 4.1 - Place both baseboards against the wall.
  • 4.2 - Locate the centre of the stud that is closest to the end of the moulding.
  • 4.3 - Cut both mouldings with a 45° angle so they overlap.
  • 4.4 - Position both baseboards in place. Measure the length needed for the second moulding to reach the other wall and cut at a right angle.
  • 4.5 - Set both pieces in place and nail into the stud to form a fit. Completely nail in the baseboards.

Pro Tip

If you need to join two mouldings along the same wall to complete the length, you can use either a square cut or a scarf joint. We recommend a scarf joint as it is less visible and provides a tighter seam. Splices should always be located over a wall stud.
Cutting angles on baseboards with outside corners
5

Cut the outside corners

  • 5.1 - Use a square to determine if the corner is a perfect 90° angle. If not, make a template with two 1' length baseboards. Take note of both angles.
  • 5.2 - Position the baseboard 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 a 45° cut 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 the required length.
  • 5.7 - Glue the outside corners before nailing them so that they stay in place and well closed.
  • 5.8 - Nail in place.
6

Finishing

  • 6.1 - Sand the joints with sandpaper.
  • 6.2 - If the baseboards were previously painted, simply touch up where needed.
  • 6.3 - Fill small cracks in the corners and between the baseboard and wall with a paintable caulking.
  • 6.4 - Wipe off any excess with a damp cloth.
  • 6.5 - Lightly sand the surface with fine sandpaper.
  • 6.6 - Apply a primer and then paint.

Related products