Door Thresholds & Sills
The thresholds inside your house and the sills and thresholds in exterior door-ways are the hardest-working parts of your doors. Because they’re exposed to continual foot traffic and, in the case of exterior doorways, the elements, both may eventually need to be replaced.
The sill forms the bottom of the frame of an exterior doorway and serves the same function as a window
sill it diverts water away from the door and house. The sill fits snugly under the casing and against or under the jambs. Fastened to the sill is a threshold, which helps seal the air space under a door. Thresholds are often used inside as well to make a neat transition between different flooring materials.
Thresholds, also called saddles, are available in either hardwood or metal (usually aluminum). You can also
get special thresholds that act as weatherstripping.
Replacing A Wood Threshold
Removing a threshold or sill. Remove a damaged threshold or sill very carefully so you don’t damage the door frame or, in the case of a sill, any flashing underneath. If necessary you can cut them out, as shown for window sills. Unscrew and remove a metal threshold. Be sure your replace-ment is long enough and measure carefully before making any cuts.
Installing a new threshold or sill.
Check that the clearance between the bottom of the door and the new thresh-old is about 1/8 inch. If it’s less, mark the bottom of the door using the new threshold as a guide, and sand or trim the door to fit. For installation instructions, see at right.
If you’re adding weatherstripping along the door bottom, follow the manufacturer’s recommendations
for clearance.
Once a wood threshold is in place, sink the nail heads and fill them. Sand the threshold smooth and coat an interior one with clear varnish or sealer. Fasten a metal threshold with screws. Be sure to finish a sill and threshold in an exterior doorway to protect the wood against the elements.
Replacing Sill
