Stand by your closed front door on a winter morning and you can usually feel the leak with the back of your hand. A worn or missing front door sweep is the single biggest reason a tight-looking entryway still bleeds heat, lets in dust, and makes the foyer floor cold. Replacing one takes under 20 minutes, costs $10 to $25, and pays for itself in a single heating season.
Part of our Windows & Doors guide — explore the full guide →
What a Door Sweep Actually Does
A door sweep is a thin strip of aluminum, vinyl, or rubber that mounts to the bottom of the door and presses against the threshold when the door is closed. Its job is to fill the gap between the door slab and the floor, where standard weatherstripping cannot reach. That gap is usually 3/8 to 5/8 inch on a residential exterior door.
Beyond drafts, a properly fitted sweep blocks light, insects, leaves, dust, and a surprising amount of street noise. On a south-facing door in summer, it also keeps cooled air inside, which trims AC runtime in long humid stretches.
Types of Door Sweeps
You will see four main styles at any home center:
- Surface-mounted (screw-on) sweeps — an aluminum carrier with a vinyl or brush flap, screwed to the inside face of the door. Easiest to install and replace.
- U-shaped slip-on sweeps — slide over the bottom edge of the door. Best for hollow-core or steel doors with no good screw bite.
- Automatic drop-down sweeps — spring-loaded; the seal lifts when the door opens and drops onto the threshold when it closes. Common on commercial fire doors and some upgraded entries.
- Door shoes — a wraparound aluminum piece with a vinyl bulb that seals against the threshold. Used when the bottom of the door is rotted and needs to be cut and capped.
How to Measure for a New Sweep
Pull the existing sweep first if you can — the part number is often stamped on the carrier. Otherwise, measure the door width at the bottom edge, not the top. Most exterior doors are 36 inches wide, but custom doors run 32, 30, or 42. Buy a sweep 1 to 2 inches longer than the door so you can trim it; aluminum cuts cleanly with a hacksaw.
Measure the gap between the bottom of the door and the highest point of the threshold with the door closed. Anything over 5/8 inch needs a brush sweep or a taller vinyl flap. Under 1/4 inch and you may only need a thin replacement insert.
Best Door Sweep Picks
After installing dozens on jobs, three keep showing up:
- M-D Building Products Heavy-Duty Aluminum and Vinyl Sweep — about $9, 36-inch length, slotted holes for height adjustment. The default I reach for on wood doors.
- Frost King E/O Brush Door Sweep — about $12, nylon brush handles uneven thresholds and pet hair without binding.
- Pemko 345 Series Automatic Door Bottom — $40 to $70, but worth it on a primary entry. The drop seal stays out of the way over rugs and tile transitions.
Step-by-Step Installation
Tools: drill, 1/8-inch bit, Phillips screwdriver, hacksaw, tape measure, pencil. Plan on 15 to 20 minutes.
- Open the door fully and prop it. If a sweep is already there, remove the screws and pull the old one off.
- Wipe the bottom 2 inches of the door clean. Old caulk or paint flakes will keep the new sweep from sitting flat.
- Hold the new sweep against the door, vinyl flap pointing toward the threshold. The flap should compress about 1/8 inch when the door is closed — not so tight that it drags hard on tile or carpet.
- Mark the door width on the sweep, then cut the aluminum carrier with a hacksaw. Trim the vinyl flush with scissors.
- Position the sweep, pre-drill through the slotted holes, and drive the included screws partway. Close the door, check the seal along the full width, then tighten down.
Common Problems and Fixes
If the door drags on carpet inside, raise the sweep in its slots and re-test. If light still shows at one corner, the threshold may be sagging — shim the threshold from below or switch to a brush-style sweep that conforms to uneven surfaces.
On steel and fiberglass doors, use #6 or #8 self-tapping screws rather than the wood screws that come in the package. They bite into the metal skin without spinning out.
When to Replace vs. Repair
Replace the sweep every 3 to 5 years on a high-use door, sooner if the vinyl is cracked or the brush has flattened. A quick test: hold a lit incense stick or a sheet of tissue along the bottom seam on a windy day. Movement means air is moving, and you are losing money.
If the door itself is rotted at the bottom or the threshold is cracked, swapping just the sweep is a band-aid. Plan a full threshold and sweep replacement together, which still runs under $80 in materials for a standard 36-inch entry.
Pairing the Sweep With Other Weatherstripping
A front door sweep handles only the bottom edge. The other three sides — top and both jambs — need their own weatherstripping for a complete seal. The most common types are V-strip (bronze or vinyl), foam tape, and kerf-in silicone bulb. V-strip is the most durable for the long sides of a wood door; kerf-in silicone is the original-equipment seal on most modern fiberglass and steel doors.
Inspect all four edges every fall before heating season starts. Run a piece of paper between the door and the jamb on each side; if it pulls out without resistance, that edge needs new weatherstripping. The combination of fresh sweep plus fresh weatherstripping seals an exterior door tight enough to pass a blower-door test in most cases.
Cost vs Energy Savings
Total spend on a quality front door sweep upgrade: $15 to $40 in materials plus 20 minutes of labor. The Department of Energy estimates air leaks around exterior doors account for 5 to 10 percent of a home’s heating and cooling losses in older houses. On a $1,800 annual energy bill, even a 5 percent improvement is $90 saved per year. The sweep pays for itself in one heating season and keeps paying year after year.
