How to Install Baseboard Molding

Baseboard molding provides a visual and physical connection between walls and adjacent flooring, door and window casings, and a home's architectural style. We share everything you need to know when choosing and installing baseboard trim.

Project Overview
  • Total Time: 12 hours
  • Skill Level: Beginner

Baseboard moldings—one of a room's last finishing trims to be installed—are meant to fill gaps between wallboard and floors, protect walls against vacuum dings and furniture scrapes, and form a pleasingly cohesive perimeter. Baseboards meet up with door casings and anchor architectural wall treatments such as paneled wainscoting.

After the walls are painted, the floors are laid, and the cabinets are installed, baseboard moldings are installed and play an essential role in how a room looks and feels. Thoughtfully chosen baseboard moldings go a long way toward emphasizing design styles that range from streamlined modern to old-world to traditional.

Installing baseboard molding is a job for anyone comfortable using power tools, making a few specialized saw cuts, and who has a knack for accurate measurements. If you think you're not up to the task, ask your friends or local building associations to recommend a reliable contractor. If you decide to go the contractor route, obtain multiple bids for comparison's sake. Ask for references, and check with the contractor's previous clients.

What You'll Need

Equipment / Tools

  • 1 Stud finder
  • 1 Hammer or nail gun
  • 1 Nail set
  • 1 Circular saw
  • 1 Compound miter saw
  • 1 Coping saw
  • 1 Measuring tape
  • 1 Block plane

Materials

  • 1 Baseboard molding
  • 1 Cap molding, optional
  • 1 Shoe molding
  • 1 8d finish nails
  • 1 Carpenters glue

Instructions

  1. Pick Your Material

    Choose a baseboard style that complements your home's architecture, suits your design aesthetic, and works with your home's existing millwork. Some popular baseboard styles include rounded base molding, Colonial-type trim with a decorative edge, fluted casings, and 4 to 6 inch high flat-plank moldings.

    Inventive configurations and creative baseboard ideas—such as stacking ready-made moldings, expanding a baseboard's presence with cap and shoe moldings, or opting for custom-crafted millwork—offer nearly endless possibilities for finishing off the bottom of your walls.

    Most home centers sell moldings of various materials and lengths that commonly range from 8 to 12 feet. Architectural molding is a durable, easy-to-handle, lightweight trim crafted of polystyrene or polyurethane that is often sold in 8-foot lengths. Medium-density fiberboard (MDF) is a lightweight engineered-wood product that comes pre-primed, so it's ready for painting. You'll also find baseboard moldings crafted of oak, pine, and hardwood in unfinished, pre-primed, stained, and painted finishes.

    Plinth blocks, corner blocks, and other specialty trim pieces are available in all materials. These pieces fit inside corners or around outside corners to accommodate straight lengths of molding, so you won't have to miter or cope edges. In addition, these specialty blocks let you join trims of different widths and profiles and adapt baseboards to fit around floors that step up or down.

    Once you've purchased baseboard moldings, let the materials sit inside your home for a week before finishing and installing the trim. This will give the material time to adjust to temperatures and conditions inside the house.

    You'll save time and protect your knees if you apply a finish to baseboard trim pieces before installing it on the walls. Protect your workplace floor with drop cloths, move in a pair of sawhorses, and set your trim pieces so you can stain, prime, and/or paint them all at once. Once the paint has dried, it's time to install the molding.

    Editor's tip: While most new houses use a one-piece baseboard, a more traditional approach is to use two or even three pieces of molding to form the baseboard. A multipiece baseboard begins with a piece of baseboard, which is installed first. It is topped with a piece of cap molding, which is small and bends easily to conform to variations in the wall. The final piece is the base shoe. To allow for seasonal movement of a wooden floor, the base shoe is nailed at a slight downward angle into the baseboard—not the floor—with finishing nails. It, too, is flexible and disguises gaps between the floor and the underside of the baseboard.

    Multipiece baseboards add a nice touch to a room. Some installations dispense with the cap molding and simply use a baseboard and base shoe.

  2. Measure Twice, Cut Once

    1. Prep room for trim installation (If replacing old trim, remove from walls and repair any wall damage that might show once new trim is installed.). Move any excess furniture, cords, curtains, etc., near the walls.
    2. Determine the number and length of pieces of baseboard, cap, and shoe molding you will need to complete the job.
    3. Measure the sections of straight wall to be trimmed. Write down the length of each wall; divide that measurement by the length of the baseboard material you'll be using. Multiply that number by 1.1 to figure the total footage you will need plus 10 percent extra for joints and scraps left over from making cuts.
    4. If you're layering on shoe and cap moldings, repeat the measurements for each type of trim.
  3. Cut Baseboard Moldings

    Use a circular or miter saw to cut boards to the correct length, allowing extra inches for miter cuts on baseboard pieces that meet at outside corners. Use a miter saw to cut 45-degree angles in trim pieces that will have mitered joints; use a coping saw to create coped joints for inside corners. Cut a baseboard piece for straight stretches of wall to reach from corner to corner. For runs longer than 5 feet, cut the pieces about 1/16 inch longer than the measurement.

  4. Do a Dry Run

    1. Lay out cut baseboards—make sure baseboards that meet at outside corners are long enough to allow for miter cuts.
    2. Remove and mark each board's location on its backside; mark a corresponding number on the wall.
    3. Use a stud finder to find wall studs, and mark their position with a pencil.
  5. Begin Installation

    1. Start installation at a convenient location, working from inside corner to outer corner.
    2. Use a nail gun to drive nails. Or, hammer two finishing nails through the board at each stud, near the top and bottom of the baseboard.
    3. Place nails at a slight downward angle.
    4. Use a nail set to drive the heads below the wood surface. The molding will bow slightly but will press tightly into position when nailed in place.
  6. Splice if Needed

    DIY trim, trim, DIY

    If needed, splice pieces. When walls are longer than the length of your molding pieces, you'll need to splice two pieces together using a scarf joint. Cut 45-degree angles on the ends of adjoining pieces, which will overlap one another. Plan the joint so it's on a stud for secure nailing. Predrill nail holes before driving nails into the joint to avoid splitting the wood. A tight-fitting scarf joint will be barely visible with a bit of glue and some judicious sanding.

  7. Nail to Wall

    1. Drive 8d finishing nails through the trim, into walls studs, and along the bottom plate. Use as many nails as needed to close gaps between the molding and the wall.
    2. Use a nail set to finish driving nails—this will prevent denting the trim's surface.
    3. Cope the end of the next piece of molding, leaving its other end long for now.
    4. After coping the end of the second piece, measure and cut it to length.
    5. Add about 1/16 inch to the length for a tight fit. If the piece runs into a door casing, use a notched piece of plywood to help mark it for length.
  8. Miter Corners

    To miter outside corners, fit the coped end of the molding first, and then mark the miter location with the piece in place. Keep in mind that corners are rarely perfectly square. You may need to adjust miter angles slightly for a good fit. Make test cuts in scrap pieces.

  9. Tighten Mitered Cuts

    If the joint has an open front, a stroke or two with a block plane at the back of the joint tightens the fit. Another way to change a miter angle slightly is to place a playing card between the miter saw fence and molding.

  10. Add Shoe Molding

    To complete the look, add shoe molding:

    Place shoe molding across the lower edge of the baseboard.

    Nail or glue the pieces in place.

    Cope inside joints and miter outside joints, gluing as needed to secure. Use scarf joints to splice trim pieces on long walls.

    Add cap molding to the top of the baseboards for a more traditional look. Set cap molding atop baseboard trim, placing it flush against the wall. Use the same technique to install the cap molding as you would with the shoe molding.

  11. Review Work

    Go back over your work. Use sandpaper to knock off sharp edges and extra adhesive. Putty and touch up nail holes with paint or stain. Add another coat of paint or stain if needed.

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