· Michael Blair
A visible gap around an exterior door is worth fixing — it is a direct air leak in a house where you are paying to condition the air. Most of the time it is adjustment and weatherstripping rather than a new door.
Find the leak first
Close the door on a strip of paper and pull. If it slides out easily, the seal is not compressing there. Repeat around the whole perimeter to map where contact is lost.
At night, have someone shine a torch around the outside while you watch from inside. Light means air.
Adjustment before parts
Most modern exterior doors have adjustable strike plates and, on many, adjustable hinges. Moving the strike a couple of millimetres often restores compression across the whole latch side.
A door that has dropped and catches on the threshold usually needs the top hinge screws driven into the framing with longer screws rather than the door being planed.
- Paper test around the full perimeter
- Adjust the strike plate before replacing anything
- Longer screws in the top hinge for a dropped door
- Adjust the threshold height if it has one
- Replace the door sweep — it wears fastest
Weatherstripping and sweeps
The compression seal in the jamb hardens and takes a set over time, and it is inexpensive to replace. Kerf-in seals pull out and push back in without tools on most doors.
The sweep at the bottom wears fastest because it drags. It is the single most common source of a visible gap and among the cheapest parts in the house.
When the door is genuinely done
A rotted bottom rail, a delaminating skin, a warped slab that no longer meets the stop along its length, or a frame that has moved with the house.
On a wood door in Middle Tennessee humidity, seasonal movement is normal and a door that binds in August and clears in January is not a candidate for replacement.