How to Replace a Threshold

Here in New England weather is a serious factor that affects the exteriors of our homes, especially windows and doors – openings that, if not maintained, can allow water to infiltrate the structure. One key component of all exterior doors is the threshold. Now this may sound old-timey, but “threshold” is simply a term for the structural transition that is part of the doorway over which the door swings. It separates the interior floor from the outside and helps make entry smoother while keeping weather out. 

In an older home an exterior threshold is often constructed with a sturdy hardwood such as oak to handle a lot of abuse from foot traffic and weather — but it can only withstand so much. If your threshold is in rough shape, it’s probably time to replace it. 

Installing a new threshold and sill will take between two and three hours. Protect your floors with a drop cloth before you begin, and make sure you’re comfortable with basic carpentry skills.  

Here are ten basic steps for replacing an old wooden threshold:

  • Remove the old threshold from the doorway using a hammer and reciprocating saw.
  • Use reciprocating saw to cut the nails securing toekick; remove toekick.
  • Test-fit new threshold in doorway.
  • Build up toekick and subfloor with pressure-treated lumber; re-install toekick.
  • Apply a bead of tri-polymer caulk to the joint between the finished floor and new threshold.
  • Install new threshold, then tap shims underneath.
  • Close the door and check for an even gap along the threshold.
  • Open the door, and apply expanding polyurethane sealant under the threshold.
  • Close the door, then tap shims between door bottom and top of threshold; leave shims in place until the sealant cures.
  • Sand threshold, then finish with an exterior paint or stain and topcoat that contains a ultra-violet protector. 

Most exterior thresholds also have a sill beneath them. If the threshold is rotted, the sill probably is, too. The sill is beveled on one side to drain water away from the house. It fits tightly between wall studs and under the jambs and casing, so it has to be cut before it can be removed.

At Bingham Lumber, we have all the materials you’ll need to renovate your entryway, making it look better and protect your home better from the elements. For a closer look at replacing a wood threshold, check out this video.