Replace a worn exterior-door threshold
Fit a matching removable threshold over a sound sill and restore the bottom seal.
Home · 2–4 hr · Medium
Before you start
Check old painted surfaces for lead before disturbance. Keep the entry secure during work. Clamp metal before sawing and wear eye protection and gloves for sharp edges. Stop if the sill or supporting floor is wet, soft or damaged.
Tools and materials
- Compatible threshold, supplied fasteners and manufacturer-approved exterior sealant
- Tape measure, square, screwdrivers, pry bar, hacksaw or suitable saw, file, clamps, eye protection and gloves
Check the problem
Confirm the threshold is removable
Identify how the threshold attaches and check the door documentation. If it is integral with the jamb or sill pan, stop rather than cutting out part of the weatherproof door unit.
Match the sealing profile
Record width, height and end notches. Check clearance beneath the door and how its sweep meets the old threshold. A different height may prevent latching or leave a draft.
Steps
Remove fasteners and release sealant
Open and secure the door. Remove threshold screws, score the old perimeter seal and lift the piece carefully. Preserve underlying flashing and use the old part as a fitting template.
Inspect and clean the sill
Remove old bedding without gouging the sill or damaging flashing. Let the surface dry. Stop for rot, moisture damage or missing drainage details before installing a cover over it.
Cut the replacement to fit
Transfer length and end notches, checking against the actual opening. Clamp the replacement, cut with a blade suited to its material and deburr every edge. Dry-fit before applying sealant.
Check the door clearance
Set the threshold in place and close the door gently. Confirm sweep contact, latch engagement and an unobstructed swing. Correct the fit now; do not force the door against an over-high threshold.
Bed and secure the threshold
Apply the threshold maker’s sealant pattern, preserving specified drainage. Seat the threshold and use the supplied fastening method with depth-controlled pilot holes. Tighten evenly without bending it.
Seal ends and verify
Finish the instructed end seals and let sealant cure. Check smooth closing, secure latching and continuous sweep contact. After rain, inspect indoors for moisture; investigate any leakage rather than adding random exterior caulk.
Finish the instructed end seals and let sealant cure. Check smooth closing, secure latching and continuous sweep contact. After rain, inspect indoors for moisture; investigate any leakage rather than adding random exterior caulk.
Tips
Keep the old piece
Its end notches are useful references, but check measurements before copying damage or poor fit.
Preserve the drainage design
Sealing every visible opening can trap water under the door.
Fix the right component
A worn door sweep may also need replacement; raising the threshold excessively is not a substitute.