A door sweep closes the gap beneath an exterior door and helps limit drafts, dust, insects, and rain splash. When the rubber is cracked or the sweep no longer touches the threshold evenly, replacing it can improve comfort without changing the whole door.
Check the gap
Close the door and look for daylight beneath it. Check whether the threshold is level and whether the door itself is sagging. A sweep cannot correct a badly misaligned door, and forcing it against an uneven threshold can make the door difficult to operate.
Remove the old sweep
Support the door and remove the retaining screws or slide the old sweep from its channel, depending on the design. Keep the screws and measure the old part before disposal. Clean dirt from the bottom edge and threshold.
Fit the replacement
Use a sweep made for the door width and bottom profile. Trim only where the instructions allow it, and keep the seal continuous across the opening. Set the height so the sweep contacts the threshold lightly rather than dragging hard.
Test the seal
Open and close the door several times, then check the seal from both sides. Look for light at the corners and confirm that the latch still engages. Recheck after rain or a temperature change, when materials can move slightly.