DIY & Repair

How to Fix Drafty Windows (Cheap Fixes First)

Before you spend on replacement, work this ladder of fixes from free to a few hundred dollars. Sometimes a drafty window needs ten dollars of weatherstripping, not a new unit.

First, find the actual leak

On a windy day, move a lit incense stick or a strip of single-ply tissue around the window: along the sash edges, where the two sashes meet, around the frame's perimeter trim, and at the sill. Watch where the smoke or tissue dances. Drafts at the sash mean worn seals or hardware; drafts at the trim mean the gap between frame and wall was never properly sealed — two different fixes.

Fix 1: Lock your windows (free)

Obvious but commonly missed: window locks are compression devices. Locking a double-hung pulls the sashes together and against the weatherstripping. If the lock will not engage, the keeper may just need a screwdriver adjustment.

Fix 2: Replace the weatherstripping (about $10 per window)

Peel out flattened, cracked foam or v-strip and replace it. For double-hungs, self-adhesive v-strip in the side channels and where the sashes meet does most of the work. Clean the surface with rubbing alcohol first so the adhesive holds through the muggy Southeast summer humidity.

Fix 3: Caulk the trim gaps (about $8)

If the smoke test flagged the perimeter, run a bead of paintable acrylic-latex caulk where the interior trim meets the wall and where it meets the frame. Outside, seal gaps between the exterior trim and siding with exterior-grade caulk — but never caulk the weep holes at the bottom of the frame, which exist to drain water (important during the region's heavy summer downpours).

Fix 4: Rope caulk or shrink film for the season (about $10 to 15)

For old single-panes you are not ready to replace: rope caulk presses into sash gaps in fall and peels out cleanly in spring. Clear shrink film over the whole interior opening adds a still-air layer that genuinely helps during the region's short cold stretches — unglamorous, effective, invisible from ten feet.

Fix 5: Cellular shades and lined curtains (about $40 and up)

Not a fix for the leak, but honeycomb shades trap an insulating air layer against the glass and noticeably soften both winter drafts and the heavy summer heat gain on bad windows — the bigger problem in this climate. Useful while you save toward replacement.

When the ladder runs out

Persistent drafts after new weatherstripping and caulk usually mean the sash or frame itself has warped, the glazing seal has failed (look for fog between panes), or air is moving through the wall cavity around the window where only removing the trim — or the window — can seal it. At that point you are no longer buying caulk; you are pricing repair against replacement, and a specialist's measure-and-quote visit costs you nothing but an hour.

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