Drafty Door — seal

Use only checks that match the exact appliance or system and its official guide.

1. Check 1

   Close and latch the door, then inspect the four sides from inside and outside for daylight, a visibly compressed or missing gasket, cracked seal material, gaps at the corners, and air movement. Use a strip of tissue near each seam on a windy or cold day to locate movement without a flame.

   Expected result: The draft is concentrated at the jamb/head weatherstrip, at the bottom edge, or around the trim and wall rather than at the door slab itself.

   Next step: Mark the leaking section and continue with the paper or card check before selecting a material.

   Why this matters

   Why: The location identifies the likely repair: perimeter gasket, threshold or sweep, or deeper frame sealing. A gap that changes when the door is lifted suggests hardware or alignment rather than only a gasket.

2. Check 2

   Place a playing card or similar thin card between the closed door and jamb at several points, including the latch side, hinge side, and top corners. Repeat at the bottom against the threshold where accessible, and pull gently without forcing the door.

   Expected result: The card is held with light resistance, slides freely at one section, or cannot be inserted because the door is already tight or binding.

   Next step: Record the loose sections, then tighten or adjust hardware and recheck the fit before installing a seal.

   Why this matters

   Why: A card that slides freely indicates inadequate compression at that location and supports weatherstrip or sweep work. A card that cannot pass or a door that binds suggests alignment or hardware needs attention before adding thickness.

3. Check 3

   Inspect the hinges, latch/strike alignment, door stop, threshold, and bottom sweep. Tighten accessible loose hinge or strike screws if the door remains square; check that the threshold is continuous and that the sweep meets it without dragging or leaving a visible gap.

   Expected result: The door closes more snugly after hardware adjustment, or the frame remains out of square, the slab is warped, or the threshold cannot be adjusted without affecting operation.

   Next step: Re-run the card test. If the remaining gap is uniform and the door operates normally, select a weatherstrip or sweep sized for the existing profile.

   Why this matters

   Why: Improved fit means the draft was partly an alignment problem. A persistent uneven gap, loose frame, warped slab, or damaged threshold needs carpentry or professional assessment before sealing.

4. Check 4

   Install or replace only the damaged perimeter weatherstrip or bottom sweep, following the product instructions and keeping the same coverage width. Close the door and check the entire seal for buckling, gaps, or excessive pressure; then repeat the tissue or card test.

   Expected result: The seal is continuous and the door latches with normal effort, or the door is hard to close, the seal buckles, or the draft remains at the frame/trim.

   Next step: If the draft remains behind the casing or at the rough opening, stop removing trim unless prepared for the relevant safety risks and arrange a qualified professional or home-energy assessment.

   Why this matters

   Why: A continuous seal with normal operation indicates the accessible leak is corrected. Binding or a remaining frame leak means the material or underlying fit is wrong; adding more thickness can worsen the problem.