Installing thresholds to hardwood flooring will give the area underneath doors and between two types of flooring a professional, finished look. Without thresholds, the carpet could fray, shoes could damage the wood, and the room could take on an unsightly, sloppy appearance. Hardwood thresholds are available in many types, colours and grain patterns to match the existing wood floors. Thresholds also provide a safe transition between floors of varying heights, reducing the risk of tripping and falling.
Remove any damaged or old thresholds from the hardwood floor with a small pry bar. Loosen the old threshold with the pry bar, using a thin putty knife under it to protect the hardwood floor. Vacuum away dirt and dust from where the old threshold used to be with a hand vacuum. Skip this step if there isn't an existing threshold.
Measure the door opening or length of area where the threshold piece will be installed, using a tape measure.
Cut the threshold to the measurements with a circular saw. Use 60-grit sandpaper to smooth the rough, cut edges of the threshold.
Place the threshold in its intended location to test its length for accuracy. Use a wood plane tool to trim the bottom of the threshold if it sits too high above the surrounding floor level. Glue wood shim pieces to the bottom of the threshold with construction adhesive if it sits too low between the surrounding floors
Lay the threshold on a stable, flat surface and drill 1/16-inch pilot holes along the length of the threshold, using a drill bit and power drill. Space these pilot holes apart at least every 6 inches.
Put the threshold back in its intended spot and use a hammer to nail finishing nails through the holes into the subfloor. Sink the heads of the finishing nails further into the holes with a nail punch.
For unfinished thresholds, take the piece to a well-ventilated location and use 60-grit sandpaper to smooth the rough wood. Buff the wooden threshold with a piece of 120-grit sandpaper and wipe the dust away with a dampened cloth. Apply wood stain to the threshold with a soft rag. Let the threshold dry before installing. If the subfloor is concrete, requiring the threshold to be glued, apply construction adhesive to the edge of the hardwood floor. Sit the threshold over the gap between the two floor types and push down on the piece to adhere to the glue. Place heavy weights on the threshold while the glue dries, which is typically two or four hours. Some retailers offer metal threshold pieces for homeowners desiring a modern look.