Home fixes & guides

How to Weatherstrip an Exterior Door to Stop Cold Drafts

I feel cold air leaking around my front (exterior) door — how do I weatherstrip it to stop the drafts?

Most drafts come from the gap under the door (fixed with a door sweep) plus the three other edges (fixed with adhesive or kerf-in weatherstrip). Find the leaks first, then match the right product to each gap — a weekend DIY job that pays for itself in lower heating bills.

ℹ️ Reference only: For general reference only. This guide does not guarantee any result — every home is different. Verify against your local building codes and a licensed professional before acting, especially for electrical, gas, plumbing, structural, or roof work.

Common causes

• The bottom gap under the door is the biggest single leak path — most homes have a 1/4 to 1/2 inch gap between the door and the threshold that no side weatherstrip can cover. (most common)
  Quick check: Slide a dollar bill under the closed door — if it slides freely, you have a gap to seal with a sweep. At night you can also have someone shine a flashlight along the bottom from outside while you watch for light inside.
• Compressed, cracked, or missing weatherstrip on the latch side and top — the old foam or vinyl has flattened over the years and no longer presses against the door. (most common)
  Quick check: Run a damp hand along the closed door's edges and feel for moving air, then inspect the existing strip for cracks, gaps, or a permanently squashed shape.
• The hinge side is overlooked — people seal the latch side and top but forget the hinge edge, which also leaks if the gap is uneven. (common)
  Quick check: Close the door and look at the gap along the hinge side from inside; if you see daylight or the gap varies top-to-bottom, it needs sealing too.
• The door is warped or out of alignment, so the gap is wide at one corner and tight at another — weatherstrip alone can't span an inconsistent gap. (common)
  Quick check: Close the door and eyeball the reveal (gap) all the way around; a consistent gap means weatherstrip will work, but a gap that goes from tight to wide signals a hinge or alignment fix is needed first.
• Wrong product for the gap size — V-strip, foam tape, felt, and rubber compression strips each suit different gap widths, and a poor choice either won't seal or will keep the door from closing. (common)
  Quick check: Measure the gap with a folded piece of paper or a feeler gauge: small even gaps suit V-strip/tension seal, larger or uneven gaps suit compressible rubber/silicone bulb strips.
• Air bypassing the weatherstrip through gaps between the door frame (jamb) and the wall framing behind the trim. (less common)
  Quick check: Pull back the interior casing trim slightly or feel along the seam where the jamb meets the wall on a windy day; cold air there means you need caulk or minimal-expanding foam behind the trim, not weatherstrip.

How to fix it

1. Find every leak first. On a cold or windy evening, close and lock the door, then move a damp hand (or a lit incense stick held well away from anything flammable) slowly around all four edges and watch where you feel air or the smoke bends. Mark those spots with painter's tape so you know exactly what to seal.
2. Measure the gaps. Close the door and check the reveal on the hinge side, latch side, and top. Note where gaps are small and even (use V-strip or tension seal) versus wide or uneven (use a compression rubber/silicone bulb strip). Slide a bill or fold a paper to gauge the bottom gap for sweep sizing.
3. Clean the surfaces. Adhesive-backed weatherstrip only sticks to clean, dry surfaces. Wipe the jamb stop and door edge with a degreaser or rubbing alcohol and let it fully dry. Scrape off any old, crumbling weatherstrip and adhesive residue first.
4. Weatherstrip the top and two sides. For adhesive V-strip: cut to length with scissors, peel and press into the corner where the door meets the stop, point of the V facing out so it compresses when the door closes. For compression bulb strip: nail or screw the flange to the door stop so the bulb just touches the closed door — snug but not so tight the door won't latch.
5. Install a door sweep on the bottom. Measure the door width, cut the sweep to length with a hacksaw, hold it against the inside bottom of the closed door so the rubber or brush fin just kisses the threshold, then screw it on through the slotted holes. Adjust up or down so it seals without dragging hard.
6. Consider a threshold or door-bottom upgrade if the gap is large. An adjustable threshold (turn the screws to raise the insert) or a U-shaped door bottom that wraps the bottom edge seals better than a basic sweep when the gap is big or the floor is uneven.
7. Address frame-to-wall leaks if found. If air came from where the jamb meets the wall behind the trim, run a bead of paintable acrylic-latex caulk along that seam, or use minimal-expanding (door-and-window) spray foam behind the casing. Never use standard high-expansion foam — it can bow the jamb and bind the door.
8. Test your work. Re-run the hand or incense test around all edges, and open and close the door a few times to confirm it still latches easily and the weatherstrip compresses evenly. Re-adjust the sweep or strip tension as needed.

DIY or call a pro?

This is a classic DIY job — no special skills, just measuring, cutting, and screwing in parts. Call a pro (carpenter or handyman) only if the door is visibly warped, the gap is wildly uneven corner to corner (an alignment, hinge, or frame problem), the door is racked in a settled frame, or you're replacing the threshold and find rot in the subfloor underneath — water damage and rot need a pro to assess.

Tools & parts

• Adhesive V-strip (tension seal) or compression rubber/silicone bulb weatherstrip
• Door sweep (or U-shaped door bottom / adjustable threshold for larger gaps)
• Tape measure
• Scissors and a hacksaw (to cut the sweep)
• Utility knife
• Screwdriver or drill/driver
• Pencil for marking
• Rubbing alcohol or degreaser and a rag
• Painter's tape
• Incense stick or a candle for the draft test
• Paintable acrylic-latex caulk and caulk gun (if sealing frame-to-wall gaps)
• Minimal-expanding door-and-window spray foam (only if needed behind trim)

Based on: U.S. Department of Energy (energy.gov) guidance on weatherstripping and caulking for air sealing; ENERGY STAR DIY air-sealing and weatherization guidance; Weatherstrip and door-sweep manufacturer installation instructions (e.g., M-D Building Products, Frost King); Reputable home-improvement how-to references (This Old House, Family Handyman) on sealing exterior doors

General home-maintenance guidance for typical US exterior doors. Your door, frame, and climate may differ; follow the instructions that come with the specific products you buy, and consult a qualified carpenter if the door is warped, rotted, or out of alignment.