Things You'll Need
Scrap baseboard wood
Paint and paintbrush
Wooden baseboard trim can create a true finished look for a room. These pieces run in straight planks that generally measure around 3 inches high and 3/8 inch thick, and they form the barrier between your flooring and the end of the wall. Installing this trim can cause trouble when the wall on which it will be installed proves uneven. Installing the straight planks against the uneven wall often leaves unsightly gaps. You can fill these gaps by bending the trim or sealing the areas with caulk to create the finished style you desire for your home.
Cut the trim to the appropriate length for your wall. Hold the trim up to the wall as if it were installed and take note of each gap between the wall and the trim. If you have multiple gaps, consider marking the areas with light pencil so that you can keep track.
Cut a 4-inch long piece of scrap baseboard with a saw. Angle each end of the piece at 45 degrees. This piece will serve as a bracer to hold the trim in place while it molds to the uneven wall. You will need a bracer for each gap between the wall and trim.
Line the bottom and top of the trim with construction adhesive. Line the trim up with the corner of the wall as straight as you can. Nail the trim to the wall, using a nail gun or hammer to install nails every 6 inches along the trim, or wherever you have studs in your wall. The adhesive will be exposed in the gapped areas.
Use brads or tacks to secure the bracers to the gapped areas of the trim. Set the other side of the bracers against the floor so that pressure from the bracer pushes the trim firmly against the wall, closing the gap. Tack the bottom of the bracers to the floor in the appropriate places and allow the adhesive to dry overnight.
Remove the tacks from the bracers. Because of the constant pressure from the bracers, the adhesive will have dried to secure the trim to the walls. The tacks will leave small holes in the trim.
Fill in tack holes, as well as the visible nail heads, with small beads of caulk. Apply caulk over the holes and wipe away excess with your finger or a moist rag before it has time to dry.
Add premium acrylic latex caulk to a caulk gun. This type of caulk will create a firm and reliable barrier, and you can paint the caulk to match the wall.
Line the trim up with the corner of the wall as straight as you can. Nail the trim to the wall, using a nail gun or hammer to install nails every 6 inches along the trim, or wherever you have studs in your wall. With the trim installed, you will be able to see the gaps between the trim and uneven wall.
Snip a 1/8 inch hole in the spout of the caulk. Squeeze caulk into all gaps between the trim and the walls. Wipe away excess caulk with a damp rag. Allow the caulk to dry overnight, sealing the gaps.
Cover over the visible nail heads with small beads of caulk. Apply caulk over the holes and wipe away excess with your finger or a moist rag before it has time to dry.
Paint the caulk sealant on the top of the trim to match your walls, hiding your repair work.
If your baseboard is thicker than 3/8 inch, it will not be flexible and may not bend as needed for the adhesive support. Use the caulk solution to fill in these gaps.