Draft mostly at the bottom edge
Cold air hits your feet, dust collects at the threshold, or the draft gets worse on windy days.
Start here: Start with the exterior door sweep and how the door meets the threshold.
Door drafts
Exterior Door Leaking Air
Direct answer: If your exterior door is leaking air, the usual cause is a bad seal at the weatherstripping or door sweep, not the whole door. Start by finding exactly where the draft is coming through, then check whether the slab is sealing poorly or hanging out of alignment.
Most likely: Most often, the fix is replacing compressed exterior door weatherstripping, adjusting a loose or sagging door on its hinges, or replacing a worn exterior door sweep at the bottom.
A drafty exterior door usually tells on itself. You may feel cold air at the latch side, see daylight at a corner, or notice the bottom edge leaking on windy days. Reality check: a small draft is usually a seal or alignment problem, not a full door replacement. Common wrong move: stuffing thicker weatherstripping into a misaligned door and then wondering why the latch stops working.
Don’t start with: Do not start by caulking random gaps or assuming you need a new exterior door. Blind caulking can hide the real leak path and make the door harder to adjust later.
Draft at the bottom only?Check the exterior door sweep first, then look at the threshold contact.
Draft at the top corner or latch side?Look for hinge sag or latch-side misalignment before buying new seals.
Last reviewed: 2026-04-04
What the draft feels like and where to start
Draft at the latch side
You feel air along the handle side, or you can see a wider gap near the strike area.
Start here: Check whether the door is pulling tight against the weatherstripping when latched.
Draft at the top corner
One upper corner leaks more than the rest, often opposite the hinge side.
Start here: Look for hinge sag, loose screws, or a door slab that is sitting crooked in the frame.
Draft all the way around
The door never seems to seal well, and light or air shows at several edges.
Start here: Inspect the full weatherstripping for flattening, tears, missing sections, or the wrong profile.
Most likely causes
1. Worn or flattened exterior door weatherstripping
This is the most common cause when the door closes normally but still leaks air around the sides or top.
Quick check: Close the door on a strip of paper at a few spots. If the paper slides out easily where the draft is strongest, the seal is not compressing enough.
2. Worn, torn, or missing exterior door sweep
Bottom-edge drafts usually come from a sweep that no longer touches evenly or has split away from the door.
Quick check: Look from outside with the door closed. If the sweep is curled, cracked, or not contacting the threshold across the full width, it is a strong match.
3. Door sag or hinge-side looseness
A sagging door opens up one corner and keeps the latch side from pressing evenly into the seal.
Quick check: Look at the reveal around the door slab. If the gap is tighter at one top corner and wider at the opposite corner, alignment is off.
4. Latch or strike not pulling the exterior door tight
If the door closes but feels loose or rattles, the slab may not be seating firmly against the weatherstripping.
Quick check: With the door latched, push on the latch side. If it moves inward noticeably, the latch is not holding the door snug enough.
Step-by-step fix
Step 1: Find the exact leak path before touching anything
You need to separate a bottom-seal problem from a side-seal or alignment problem. They look similar from across the room but repair differently.
- Close and latch the exterior door fully.
- On a cool or windy day, move your hand slowly around the top, latch side, hinge side, and bottom edge to feel where air is strongest.
- Look for daylight at the perimeter from inside with the room lights off if needed.
- Check whether the draft is concentrated at one corner, one side, or only the bottom.
- Note whether the door also rattles, rubs, or needs a hard push to latch.
Next move: You now know whether to focus on the sweep, weatherstripping, or door alignment first. If you cannot pinpoint the leak because air is moving around trim or wall cavities, inspect the frame and surrounding trim for separate air leaks before blaming the door slab alone.
What to conclude: A localized draft usually points to one failed sealing point. A broad draft around multiple edges often means worn weatherstripping or a door that is sitting out of square.
Stop if:
- You find water staining, soft wood, or rot in the jamb or threshold area.
- The frame itself is loose in the wall opening.
- The door glass or sidelights appear to be the actual leak path rather than the door perimeter.
Step 2: Check the exterior door weatherstripping for compression and gaps
Weatherstripping is the most common fix, and it is easy to inspect without taking the door apart.
- Open the door and inspect the weatherstripping on the jamb head and both sides.
- Look for flattened sections, tears, hardened material, missing corners, or spots where the seal has pulled out of its kerf or track.
- Close the door on a strip of paper at several points around the draft area, then tug the paper out gently.
- Compare the feel at the leaking spot to a spot that seems sealed well.
Next move: If the weatherstripping is visibly damaged or the paper test is loose only where the draft is, replacing the exterior door weatherstripping is the right next move. If the weatherstripping looks healthy but one corner still leaks, move on to alignment and latch checks.
What to conclude: Bad weatherstripping causes even a well-hung door to leak. Good weatherstripping with uneven contact usually means the door is not sitting right in the opening.
Step 3: Inspect the bottom seal and threshold contact
Bottom drafts are often blamed on the threshold when the real failure is a worn sweep on the door itself.
- Open the door and inspect the exterior door sweep along the bottom edge.
- Look for torn fins, a bent carrier, missing fasteners, or a sweep that no longer reaches the threshold evenly.
- Close the door and check from outside or inside whether the sweep contacts the threshold across the full width.
- If the threshold is adjustable, note whether it is obviously set too low, but do not crank it up yet if the door is already rubbing.
Next move: If the sweep is damaged or not contacting the threshold evenly while the rest of the door fits well, replace the exterior door sweep. If the bottom leak is paired with a crooked reveal or a top-corner gap, the door is likely sagging and needs alignment first.
Step 4: Correct hinge sag or latch-side looseness
A door that hangs low or does not pull tight will keep leaking even with new seals.
- Check all hinge screws on the door and jamb side for looseness and tighten them snugly by hand.
- Pay special attention to the top hinge, since that is where sag usually shows up first.
- Close the door and look at the gap around the slab. A wider gap at the top latch corner and tighter gap at the top hinge corner usually means sag.
- If the latch side feels loose when closed, inspect the strike area to see whether the latch is fully engaging and pulling the door in tight.
Next move: If tightening hinge screws improves the reveal or the latch now pulls the door snug, recheck the draft before replacing any seal parts. If the door still sits crooked, the screw holes are stripped, or the frame has shifted, the repair may need shimming, hinge work, or jamb correction beyond a simple seal replacement.
Step 5: Replace the confirmed seal part or call for frame repair
Once you know whether the leak is from the side seal, bottom seal, or door fit, you can make a clean repair instead of guessing.
- Replace the exterior door weatherstripping if the seal is flattened, torn, missing, or failing the paper test while the door alignment is otherwise good.
- Replace the exterior door sweep if the draft is mainly at the bottom and the sweep is worn or not contacting the threshold evenly.
- Replace a damaged exterior door hinge only if one is bent, loose at the knuckle, or no longer holding alignment after screw tightening.
- If the door still leaks because the frame is out of square, the threshold is rotted, or the jamb is loose, stop patching and schedule a door repair carpenter or handyman who handles entry door alignment.
A good result: The door should latch normally, compress the seals evenly, and stop leaking noticeable air at the repaired edge.
If not: If new seals still do not contact evenly, the problem is not the seal material. The opening or hardware needs correction before more parts will help.
What to conclude: Seal parts fix seal failures. They do not fix a twisted frame, a sagging slab, or structural movement around the opening.
Replacement Parts
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FAQ
Why is my exterior door leaking air at the bottom?
Most bottom-edge drafts come from a worn exterior door sweep or poor contact with the threshold. If the top and sides feel sealed but cold air hits your feet, inspect the sweep first.
Can bad weatherstripping really cause a big draft?
Yes. Once exterior door weatherstripping gets flattened or hard, it stops compressing against the door slab. Even a small gap can feel like a strong draft on a cold or windy day.
Should I caulk around the inside trim to stop the draft?
Not until you know the draft is coming from the trim area and not the door seal itself. If air is leaking past the slab, caulking trim will not fix the real problem.
How do I know if the door is sagging instead of just needing new weatherstripping?
Look at the gap around the door. A sagging exterior door usually shows an uneven reveal, often with a wider gap at the top latch corner and a tighter gap at the top hinge corner.
Do I need a whole new exterior door if it leaks air?
Usually not. Most draft complaints come down to exterior door weatherstripping, an exterior door sweep, hinge sag, or a latch that is not pulling the door tight. Full replacement makes sense only when the slab, frame, or threshold is badly damaged or out of shape.