What you need to do before you start

A door threshold is the strip of wood, metal, or composite material that sits at the bottom of a doorway, between the inside and outside. When it cracks, warps, or no longer seals properly, water leaks in and the door stops closing tight. Replacing it is a job you can do yourself with basic tools — no special skills required, though the work takes two to four hours depending on how stuck the old threshold is.

Before you buy a replacement, measure the width of your doorway from inside edge to inside edge of the frame. Write down the exact measurement. You will also need to know whether your threshold is wood or metal, because that affects how it comes out and what you buy to replace it. Take a photo of the old threshold from the side so you can see its profile — the shape matters when you order the new one.

You will need a pry bar, a hammer, a utility knife, a caulk gun, exterior-grade caulk, and the new threshold itself. If the old threshold is screwed down, you will also need a drill or screwdriver. Have a shop vacuum or broom nearby because old wood splinters and debris scatter.

Key Takeaways

  • Measure your doorway width before you shop, and photograph the old threshold from the side so you know what profile to order.
  • The old threshold usually comes out by prying from underneath with a flat bar, though screwed thresholds need the fasteners removed first.
  • Clean the frame thoroughly with a utility knife to remove old caulk and debris, or the new threshold will sit unevenly.
  • Set the new threshold in place, shim it level, then screw or nail it down and seal the edges with exterior caulk.
  • Let caulk cure for the time stated on the tube — usually 24 hours — before you close the door fully or expose it to rain.

Remove the old threshold by prying it up

Start by checking whether the old threshold is fastened with screws or nails. Look at the top surface and the underside. If you see screw heads, remove them with a drill or screwdriver — this makes the threshold much easier to lift. If it is nailed, you can pry it out directly.

Slide a flat pry bar under the threshold from the outside, as close to one end as you can get. Tap the pry bar with a hammer to drive it underneath. Once it is wedged in, lean on the handle to lift the threshold slightly. Move to the other end and repeat. Work your way along the length, lifting a little at each point, until the threshold breaks free from the frame.

Old thresholds are often glued down as well as fastened, so expect resistance. If it will not budge, run a utility knife along both long edges where the threshold meets the frame to cut through any caulk or adhesive. Then try prying again. Once it comes loose, pull it out by hand and set it aside.

Clean the frame and check that it is level

The frame underneath the threshold will have old caulk, adhesive, dirt, and wood splinters. Use a utility knife to scrape all of this away. Work carefully so you do not gouge the wood or metal frame itself. A shop vacuum picks up the debris as you go, which keeps you from breathing it in.

Once the frame is clean and bare, set a level across it from side to side. The frame should be level or slope very slightly toward the outside (so water runs out, not in). If it is not, you will need to shim the new threshold when you set it in place. Mark any high or low spots so you know where to add shims.

Wipe the frame with a damp cloth and let it dry completely. Any moisture or dust will prevent the new threshold from sitting flush and will interfere with the caulk seal.

Set the new threshold in place and shim it level

Slide the new threshold into the opening from the outside. It should fit snugly between the frame sides. If it is too wide, you may need to trim it with a saw — most thresholds come slightly oversized for this reason. Check the manufacturer's instructions for how to cut yours without damaging the finish.

Once it is in the opening, check the level again. If the frame was uneven, slip shims under the threshold at the low spots until it is level. Shims are thin wedges of wood that you can buy at any hardware store. Tap them in gently with a hammer until the threshold sits solid and does not rock.

Press down on the threshold at several points to make sure it is seated firmly. There should be no gaps between the threshold and the frame. If you feel movement or hear a hollow sound, add more shims or adjust the ones you have.

Fasten the threshold and seal the edges

Drill pilot holes through the threshold into the frame at the locations specified in the manufacturer's instructions — usually every 12 to 16 inches. Use screws rather than nails if you can, because screws hold better and are easier to remove later if the threshold needs replacement again.

Drive the screws in firmly but do not overtighten them, which can warp the threshold or crack it. The threshold should be snug against the frame but not under tension.

Once the threshold is fastened, run a bead of exterior-grade caulk along both long edges where the threshold meets the frame. Use a caulk gun and explore a smooth, continuous line. Wet your finger and run it along the caulk to smooth it and press it into the gap. This seals out water and prevents drafts.

Let the caulk cure before you use the door

Check the caulk tube for cure time — most exterior caulks take 24 hours to set fully. Do not close the door hard or expose the threshold to rain until the caulk has cured. If you have to use the door before then, close it gently.

Once the caulk is dry, test the door. It should close smoothly without binding, and you should not see daylight or feel a draft at the bottom. If water still leaks in during rain, the caulk may not have sealed properly — let it cure fully, then inspect the seal and add more caulk if needed.

Frequently Asked Questions

Can I replace a threshold without removing the door?

Yes. You do not need to take the door off its hinges. The threshold sits below the door frame, so you can remove and replace it while the door stays in place. Just make sure the door is open while you work so you do not accidentally close it on yourself or the pry bar.

What if the new threshold is too wide for my doorway?

Most thresholds come slightly oversized so you can trim them to fit. Use a circular saw or miter saw to cut the width down. Mark the cut line with a pencil first, and wear safety glasses. Cut slowly to avoid splintering the edges. Sand the cut edge smooth before you install it.

Do I need to remove the door to replace the threshold?

No. The threshold sits below the door frame and does not interfere with the door itself. Leaving the door in place actually makes the job easier because you can use it as a reference for level and fit.

What type of threshold should I buy?

Match the material and profile of your old threshold. Wood thresholds work for interior doors and covered exterior doors. Metal or composite thresholds are better for exterior doors exposed to weather because they resist rot and warping. Take a photo of the old one to the store so the staff can help you find the right match.

How do I know if my threshold is level?

Use a 2-foot or 4-foot level and set it across the threshold from side to side. The bubble should sit in the center, or slope very slightly toward the outside. If it tilts toward the inside, water will pool and leak. Shim under the low side until it is level or slopes outward.