Door Drafts: How to Weatherstrip a Door

Quick answer

Find where air enters (jamb sides, top, or bottom gap). Install jamb weatherstripping that compresses when the door closes, and add a door sweep if light shows under the door. Measure gaps first—see measuring for a door—and add this task to your fall or winter checklist.

A drafty exterior door wastes heated or cooled air and makes rooms uncomfortable near the entry. Weatherstripping closes gaps between the door and frame. It is a straightforward DIY task when the door and frame are sound—but it will not fix a door that will not latch or a rotted sill.

Find the leak before you buy

On a windy day, hold your hand along the jamb (sides and top) and along the threshold. At night, a flashlight on one side while someone looks from the other can reveal light gaps.

Note whether the door binds or has a large uneven gap. Binding after install means the strip is too thick or the door needs hinge adjustment.

Choose weatherstripping type

Foam tape (adhesive): Cheap, fast, short life—okay for low-traffic interior doors, less ideal for main exterior entries.

Vinyl bulb or compression strip (screw-on): Common on exterior jambs; replaces worn factory strip.

Door sweep: Metal or plastic carrier with flexible vinyl or brush; mounts to door bottom.

Kerf-in strips: Fit into a slot milled in the jamb—match profile if replacing existing kerf strip.

Buy enough length for both sides and the head jamb, plus sweep width matching door width.

Tools and materials

• Tape measure—reading guide
• Utility knife or tin snips
• Screwdriver or drill
• Cleaning supplies for the jamb (remove old adhesive and dirt)

Wear eye protection when cutting metal sweep channels.

Install jamb weatherstripping

1. Remove old strip and adhesive residue. A clean surface helps adhesive types stick; screw-on types need flat mounting.
2. Close the door and mark where the door face meets the jamb.
3. Install strip so it compresses slightly when latched—not so tight that the latch misses.
4. Start at the head jamb, then sides, following product orientation (some bulbs face inward).
5. Test latch and operation before trimming excess.

Why compression matters: the strip must touch the door when closed. Too loose = still drafty. Too tight = worn hinges and hard-to-turn knobs.

Install a door sweep

1. Measure door width between casings.
2. Cut sweep to width per instructions (often inset slightly from casing).
3. Mount so flexible seal just touches the threshold or floor when closed—minimal drag.
4. Open and close several times; adjust height screws if provided.

On carpet, sweeps may need more clearance than on hard flooring.

Adjust before replacing the door

Try these if gaps are uneven:

• Tighten hinge screws (replace stripped screws with longer wood screws into framing if needed—do not strip holes)
• Adjust strike plate slightly if latch alignment is off
• Plane or trim only if you have carpentry experience—easy to remove too much

See how to measure for a new door if the slab is warped, water-damaged, or undersized for the frame.

DIY limits

Call a carpenter or door installer for:

• Rot in jamb, sill, or door bottom
• Large daylight visible when latched with frame out of square
• Entry doors with integrated multipoint locks needing factory parts
• Lead-painted surfaces in pre-1978 homes—follow EPA RRP rules before disturbing paint

Seasonal maintenance

Add door seal checks to fall maintenance before heating season and winter tasks. Replace crushed foam and worn sweeps when they no longer compress.