How to Replace a Door Threshold

A worn-out, drafty door threshold is more than an eyesore—it leaks energy, lets water in, and can damage flooring and framing.

The good news: replacing it is a fast, affordable DIY you can complete in under two hours. Follow this step-by-step guide with pro tips for a tight, weather-sealed fit on the first try.

Project Overview

• Time Required: 1–2 hours
• Skill Level: Beginner to Intermediate
• Estimated Cost: $25–$75

Safety first:

• Eye and hearing protection when cutting or prying.
• Use cut-resistant gloves when handling aluminum or sharp edges.
• If you expose older paint, consider lead-safe practices in pre-1978 homes.

Phase 1: What Should You Choose and Buy for a Perfect Fit?

Measure width, depth, and height before you shop; then choose the material that matches your climate, traffic, and maintenance goals.

How to Measure for a Perfect Fit

• Width: Measure the clear distance between the bottom ends of the door jambs. This is your overall threshold length.
• Depth: Measure from the exterior edge of the existing threshold to its interior edge. Match or slightly exceed it to cover flooring gaps.
• Height: Confirm the new threshold will fit under the door sweep/leaf without binding. If your old one was adjustable, plan on an adjustable replacement for fine-tuning.

Pro check:

• Identify door swing:Inswing doors seal on the interior face of the threshold; outswing doors seal on the exterior edge or bumper. Buy the correct profile.

Material Matters: Aluminum vs. Wood vs. Composite

Tip: If you routinely fight drafts, choose an adjustable aluminum threshold and replace the door sweep at the same time for best results.

Phase 2: What Tools and Materials Do You Need?

Answer first: Basic carpentry tools plus 100% exterior silicone sealant and the new threshold.

• Tools
  • Pry bar
  • Hammer
  • Oscillating multi-tool or jigsaw
  • Tape measure
  • Utility knife
  • Caulking gun
  • Screwdriver/drill and bits
  • Screw extractor (for stripped screws)
  • Wood file or sanding block
• Materials
  • New threshold (correct width/depth, inswing/outswing profile)
  • 100% silicone exterior sealant
  • Screws (often included with adjustable models)
  • Painter’s tape and rags

Phase 3: How Do You Remove the Old Threshold?

Unscrew it, cut the caulk, pry it free, and clean the sill to bare, dry material.

1. Remove all visible screws
   • If stripped, use a screw extractor or cut a new slot with a multi-tool and back them out with a flathead.
2. Score caulk lines
   • Run a utility knife along interior and exterior edges to break the seal without tearing flooring or trim.
3. Pry the threshold out
   • Start at one end; lift gradually to avoid splintering jambs or flooring.
   • Troubleshooting (Stuck threshold): Use an oscillating multi-tool to cut the old threshold in the middle. Removing it in two halves relieves tension and protects the jambs.
4. Clean the sill
   • Scrape away old sealant and debris. Vacuum dust. The surface must be clean, flat, and dry for the new seal to bond.

Pro tip: Probe the corners of the sill. Soft or rotten wood suggests a more significant issue—please take a moment to review our explainer on Door Sill vs. Threshold. Consider adding a sill pan and repairing framing before proceeding.

Phase 4: How Do You Cut and Fit the New Threshold?

Answer first: Dry fit first, transfer jamb locations, notch around door stops, then fine-tune for a snug, gap-free fit.

1. Dry Fit and Mark
   • Place the new threshold in the opening (it may be long—normal).
   • Using a pencil, mark the points where both the inside and outside faces of the jambs meet the threshold.
2. Master the Notch Cut (Mini-Masterclass)
   • Most thresholds must notch around the vertical door stops/jambs to slide fully into place. Hold the threshold against the opening and transfer the stop/jamb profile onto the threshold ends. Include any rabbet or step in the jamb. Add a small clearance (≈ 1/16 in) so it slides in without binding.
3. Make Your Cuts
   • Use a jigsaw for straight/curved sections and an oscillating tool to square inside corners.
   • Deburr edges with a file for a tight, clean look.
4. Test the Fit
   • Place it in the opening. It should be snug with minimal gaps at jambs.
   • Fine-tune with a file/sander. Patience here pays off in appearance and sealing.

Pro tip: Keep the factory-drilled screw holes if present—avoid cutting away critical adjustment points on adjustable models.

Phase 5: How Do You Install and Weatherproof the New Threshold?

Lay continuous silicone beads, set and fasten the threshold, then fine-tune adjustable caps to kiss the door sweep evenly.

1. Apply Sealant Like a Pro
   • On the cleaned sill, run 2–3 continuous beads of 100% exterior silicone where the threshold will sit—one near the interior edge, one near the exterior, and one centered.
   • Add a small bead at both end dams where the threshold meets the jambs to block corner leaks.
   • If your threshold has weep features, don’t block them—apply sealant behind/around, not over the channels.
2. Set the Threshold
   • Press it firmly into place. Wiggle slightly to work out the bond.
3. Fasten It Down
   • Drill pilot holes (if needed) and drive screws. Do not overtighten—you can distort aluminum caps or strip wood.
   • For concrete substrates, use masonry-compatible fasteners and seal against moisture.
4. Final Touches
   • For adjustable thresholds, turn the adjustment screws to raise the cap until it makes light contact, even with the door sweep across the full width. Use a dollar bill to confirm that a slight drag indicates a good seal.
   • Tool away any squeeze-out with a damp cloth. Allow sealant to skin before foot traffic, per label.

Pro tip: After adjustment, close the door and look for daylight. No light should show. Adjust sweep and threshold until the seal is even.

Conclusion: A Perfect Seal and a Professional Look

That’s it: careful removal, accurate notch cuts, and generous silicone are the keys to a durable, draft-free threshold. You’ve just completed a high-impact project that improves comfort and lowers energy bills.

Next step: ensure the rest of your door is sealed tight—learn How to Install Weatherstripping.