The tools you need to weatherize doors and windows

You can feel this job before you buy anything. On a windy day, hold a dollar bill against the latch side of the front door and close it. If the bill slides out, the stop is not kissing the door. Same test at the bottom: if you see daylight on the sill, the sweep is dead. Windows that rattle in the track are the same leak with a different shape.

The weatherize before the heat pump page is why envelope work belongs before a bigger outdoor unit. This page is the kit for doors, windows, and the attic hatch you can finish without becoming a weatherization contractor. Attic air sealing around cans, ducts in the crawl, and spray foam in wall cavities are still hire jobs.

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How much is this actually worth?

ENERGY STAR’s modeled estimate is that air sealing plus insulation in attics, floors over crawl spaces, and the rim joist (the wood band where the house sits on the foundation) saves an average of 15% on heating and cooling in a typical existing U.S. home, or about 11% on the whole energy bill. DOE’s Energy Saver guide puts sealing uncontrolled leaks at 10% to 20% on heating and cooling bills, and says insulation comes after air sealing.

ENERGY STAR: estimated savings methodology

DOE Energy Saver guide (PDF)

A new sweep will not hit those numbers by itself. Those figures assume a house that got sealed at the top, not just a vinyl flap on the front door. The door and hatch are still the leaks you walk past every day, so they are the part of that work you can actually finish.

HomeGuide’s 2026 weatherstripping cost page (Daniel Bal, February 5, 2026) puts a typical whole-house job at $130 to $470, with materials from $0.16 to $4.00 per linear foot if you buy the parts yourself. A contractor-installed door runs $35 to $90. A window is $5 to $10. An attic door is $35 to $90, same band as a hinged exterior door.

HomeGuide: weather stripping installation cost

If you have two exterior doors, a couple of cranky windows, and a hatch, the contractor row adds up fast even though each line looks cheap. The kit on this page is that same work when the frame is sound and you can still close the door.

What am I sealing, exactly?

Three places leak more than people think, and they take different parts.

The door bottom. A sweep screws to the inside face of the door and wipes the threshold. If the vinyl is cracked or the aluminum is bent, replace the sweep. Do not pile on a stuffed snake if the door still has to swing.

The door stop (top and sides). That is weatherstrip in a kerf (a slot in the jamb) or a screw-on kit on the stop. Kerf kits press in. Screw-on kits need a hacksaw and the screws in the box. Look at your jamb before you order. A slot wants rubber. Bare wood wants the aluminum-and-vinyl kit.

Windows that still work. V-seal (a plastic strip that folds into a V) sticks on the side of the sash or the frame and compresses when you close the window. It is for a window that latches. A sash that is rotten, painted shut, or showing daylight around the whole frame is a replacement quote.

The attic hatch. A simple ceiling panel wants gasket on the stop it sits on. Pull-down stairs are a hole the size of a door. Foam tape on the hatch is still worth doing; the stairs themselves often want a cover that fits the opening, measured, not guessed.

Pacific Northwest National Lab’s Building America Solution Center walks the same split: pick the product to the gap, clean the surface, then open and close the door or window so you know you did not lock yourself out. Their attic-hatch guide is blunt about adhesive foam: it peels off dusty wood, so wipe first, and treat the hatch as a gasketed lid, not a decorated hole.

PNNL: add weatherstrip to windows and doors

PNNL: air seal and insulate attic access

Door sweep

Frost King’s A79WHA is a 2-inch-wide aluminum holder with reinforced rubber, 36 inches long. You cut it to the door width with a hacksaw, hold it so the rubber just kisses the sill, and drive the screws on the interior face. If the sweep drags so hard the door will not latch, raise it a sixteenth. If it misses the sill, the threshold is worn or the door has sagged, and more rubber will not fix the hinge.

Exterior doors first. An interior door to an unheated garage is the second one worth doing. Bedroom doors usually are not, because you are not trying to condition the hallway against the bedroom.

If the threshold itself is chewed, rusted through, or sitting in a puddle every rain, stop. A sweep cannot invent a sill. That is a carpenter or a door shop, and HomeGuide’s door line already assumes the opening is still a door.

Door stop: kerf or screw-on

Open the door and look at the stop, the thin strip the door hits. If you see a slot with old, flattened vinyl, pull the old piece out with pliers and press in new kerf rubber. Start at a top corner so you do not leave a gap at the latch. M-D’s Platinum 84-inch brown TPV rubber (model 91891) is that refill: cut with scissors, press in, seals a gap up to about 1/2 inch as they specify.

No slot: use a screw-on kit. M-D 49002 is a three-piece aluminum-and-vinyl set (one 36-inch head, two 84-inch sides) with screws, for doors up to 36 inches wide. Cut with a hacksaw. The vinyl bulb should compress against the closed door. If you crank it so hard the door will not latch, back the screws out and move the kit toward the stop.

Do one exterior door completely (sweep plus stop) before you open three other kits. You will learn whether your jambs are kerf or screw-on, and you will not order the wrong second door.

A magnetic kit is for a steel door with a matching steel jamb. If your door is wood, skip the magnet listing even if the photo looks similar.

Windows: V-seal, not foam in the track

Frost King V-seal is 7/8 inch by 17 feet, adhesive, with a fold that squishes into the gap. Clean the frame so the adhesive sticks. Close the window and see where it actually hits. Put the V on that line, not on the glass. One roll does a couple of average windows. A drafty slider or a casement that never quite meets the frame is the right use. A window with daylight on all four sides, soft wood, or a sash that falls out of the track is not.

Do not shoot expanding foam into a window channel. It can bow the frame and you will not get the sash out. Foam in a can is for the rough gap around a new window after the flashing, which is a different job and usually a different person.

Interior-side film kits are a winter bandage on glass you are not replacing this year. They are not weatherstrip. If the sash still moves, V-seal is the product. If the sash is painted shut, leave it shut until you are ready to replace the unit.

Attic hatch

A plywood hatch that lifts out sits on a stop. Clean the wood, then stick a medium-gap rubber gasket on that stop so the hatch lands on it. Duck’s heavy-duty EPDM strip (3/8 by 1/4 inch, 17 feet, two pieces) is enough for a typical hatch and a leftover door. The adhesive hates dust. Wipe first.

Pull-down stairs are a bigger hole. Measure the opening. A cover that fits about 25.5 by 54 inches is a common size; buy to the tape, not to the photo. Weatherstrip on the door of the stairs still helps. The cover is extra if you use the attic twice a year.

If you can see insulation missing at the edges of the hatch, or daylight around the frame, that is the weatherize story again: the hatch is one leak in a leaky attic. Gasket the hatch. Do not pretend the rest of the attic is done.

A rigid-foam lid on a lift-out hatch (cut slightly smaller than the opening, foil tape on the edges) is the upgrade after the gasket, and it is still a parts job. Blowing new cellulose over open plumbing stacks is not.

What should already be in the drawer?

You probably own these. If you do not, a neighbor does, and they are a poor Amazon hunt compared with the sweep and the kerf rubber.

• A hacksaw or metal snips for the sweep and the screw-on kit
• Scissors for kerf rubber and V-seal
• A screwdriver or a drill for the sweep screws
• Rubbing alcohol or a damp rag, because adhesive on dusty paint is a waste of a roll
• A tape measure, because a 36-inch sweep on a 32-inch door is a cut, not a force fit

Skip a new drill. This is not grab-bar work.

A worked pair of doors

Say you have a front door that fails the dollar-bill test, a garage walk-through that shows daylight at the sill, two double-hung windows that rattle, and a lift-out hatch. HomeGuide’s contractor math on that list is two doors at $35 to $90 each, two windows at $5 to $10 each, and an attic door at $35 to $90. That is $115 to $290 before anyone looks at a French door or a slider.

The kit version is one kerf refill or one screw-on set per door, a sweep per door that needs the sill, one V-seal roll, and the hatch gasket. You still spend an afternoon, and you still have to look at the jamb. You do not spend the whole-house $130 to $470 line unless you also hire someone to do every window in the house.

If the front door still leaks after a new sweep and a new stop, the door is out of square or the frame is soft. That is when HomeGuide’s door number stops being the useful comparison, because you are no longer buying weatherstrip. You are buying a door.

How do I actually finish this?

1. Do the dollar-bill test on every exterior door and on the garage walk-through, and write down which ones fail.
2. Look at each failing jamb and decide slot or no slot before you order, then add a sweep for each door that shows daylight at the sill.
3. Install one door completely: sweep first, then the stop, then close it and try the bill again.
4. V-seal the two worst windows that still latch.
5. Gasket the attic hatch, and measure pull-down stairs if that is your access.
6. Stop when the next gap is spray foam, a spongy sash, or a door that will not latch after a reasonable adjustment.

When should I put the kit down?

Stop if the door frame is rotten, if the door does not latch after a reasonable adjustment, if you can see daylight around the entire window sash, or if the glass is loose in the frame. Those are carpenter and window-shop quotes. More weatherstrip on bad wood is a draft with extra vinyl.

A whole-house air-sealing crew is the right call when the attic, the rim joist, and the ducts are the real leak. This kit is for the doors you use every day and the hatch you keep forgetting.