How to Replace a Wood Door Sill

wooden double doors
  • 3-4 hours
  • Beginner
  • 50-300
What You'll Need
Pry bar
Wood sill plank
Circular saw
Penny nails (16)
Painters caulk
Deck screws
Measuring tape
Wood block

The wooden door sill is best described as being the foundation of the door frame. The wood sill is located under the door threshold. The wood sill is usually only located on exterior doors but sometimes in rare circumstances, an interior door will also have a wood sill. Replacing the sill is relatively simple. If there are small holes, these can be patched with epoxy putty. If the wood sill has missing pieces or are soft, then the sill will have to be replaced, and the article below will show you how.

Step 1 – Remove the Threshold

In order to remove the threshold, you will need to prop the door open. The threshold is located under the door and exists as the plate you will see. Use the screwdriver to remove the screws that are present and set them off to the side. Lift the threshold away from the floor and place it off to the side for later.

Step 2 – Remove the Existing Wood Sill

The wood sill is directly under the threshold. Use the hammer and gently tap one end of the pry bar under the sill at one end. Apply pressure to loosen the nails and then move the pry bar along the sill, applying pressure as you go. Remove the sill from under the door jamb. Pry the wood sill up toward the outside of the exterior door. If there are nails that will not loosen, use the circular saw to cut them through the center. Set the removed sill off to the side to use as a reference.

Step 3 – Make the New Sill

Measure the sill that you removed and cut the new plank to match the length. Make sure the ends of the new plank match the ends of the original wood sill. Use the jigsaw to cut out the notches as referenced on the old sill. Test fit the new plank and make adjustments if needed in order to make the piece fit. Sand the plank down and bevel the edge that comes in contact with the jamb, then primer and seal the top and bottom.

Step 4 – Install the Wood Sill

You will have to wait for the primer to dry before placing the wood sill back in the threshold. Place the sill in threshold, place a wood block over, and use the hammer to hit the block, which will safely push the sill in place. When the new sill is in place, use the nails and the hammer to attach it to the wall-sill. You will want to use four nails spaced the width of the sill. Apply the caulk along the edges of the wood sill to seal it. Once the caulk is dry, paint the wood sill with semi-gloss latex paint. This paint will help to protect the wood from the elements. Use the instructions on the paint to determine optimum drying time. You can then replace the threshold.