How to Fill in Gaps in Wood

Kevin McDermott

When you're installing wood trim, window frames or other wood, you'll likely have to deal with gaps between the pieces of wood, and between the wood and surround material (usually walls or floors). These are two different issues and require two different approaches, in conjunction with each other.

The goal is to get the wood looking like one solid piece, without gaps on or around it.

  1. Scoop up a little wood putty on the end of your putty knife and press it into any gaps, gouges or holes within the surface of the wood, or between two abutting pieces of the wood. Don’t put putty in gaps around the wood, such as the gap between a piece of floor trim and the surround floor and wall. Press the putty all the way into the space. Let the putty dry overnight.

  2. Sand the surface of the putty smooth with sandpaper, getting it even with the surrounding wood.

  3. Apply paint or stain and gloss to the wood. Let the finish cure for several days.

  4. Insert your caulk tube in the caulk gun. Cut the end of the tube with a razor knife, making a hole at the end that's 45 degrees and about 1/4 inch across. Jam a long nail into the hole to break the seal of the caulk.

  5. Hold the tip of the gun against the gap between the edge of the wood and the surrounding floor, wall or other surface. Squeeze the trigger of the caulk gun and pull it slowly backward, filling the gap with a smooth line of caulk.

  6. Tip

    Make sure the wood is clean, dry and free of any loose or splintering areas.