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How to Fix a Storm Window: Glass, Screen, Frame, Hardware, and Weatherstripping (2026)

Storm windows extend the life of single-pane windows and reduce heating bills — but their glass cracks, screens tear, frames corrode, and weatherstripping compresses over time. This guide covers every common storm window repair: replacing glass, patching or replacing screens, re-sealing frames, and fixing stuck or broken lift hardware.

Quick Answer

To fix a storm window: (1) Cracked glass — remove the panel, press out the old glass, cut new glass 1/8 inch smaller than the opening, bed it in glazing compound, and secure with glazier's points. (2) Torn screen — roll out the old spline and screen, cut new screen material 1 inch larger than the frame, press it in with a new spline using a rolling tool. (3) Weatherstripping failure — peel off the old foam tape or pile, clean the channel, and press in new pile weatherstripping cut to length. (4) Stuck or corroded hardware — clean with penetrating oil and replace the latch or lift rail if broken. Most repairs cost $5–$30 in materials.

Frequently Asked Questions

What is the difference between a triple-track storm window and a two-track storm window?

Track count refers to the number of channels in the frame that hold sliding panels. (1) Two-track storm windows have two channels: one for a glass panel and one for a screen panel. You manually swap the glass panel for the screen panel with the seasons — remove the glass, store it, and slide the screen in. (2) Triple-track storm windows have three channels: two glass panels and one screen panel. The bottom glass panel slides up, the screen slides down to meet it, and the upper glass panel remains fixed — all without removing any panels. Triple-track windows are more convenient (no seasonal panel swapping) but more complex to adjust and more expensive to repair when tracks bind or panels are damaged. Both types are repaired using the same techniques for glass, screen, and weatherstripping replacement.

How do I measure and cut replacement glass for a storm window panel?

Storm window glass replacement: (1) Remove the panel from the track by lifting it up and swinging the bottom out. Lay it flat on a workbench. (2) Remove the old glass: on aluminum storm window frames, the glass is typically held in a rubber or vinyl glazing channel (a U-shaped gasket around the perimeter). The corner keys (small plastic or metal corner connectors) can be pushed out to disassemble the frame, allowing the glass to slide out. On wood storm window frames, glass is bedded in glazing compound and held with glazier's points. (3) Measure the opening: measure from inside rabbet edge to inside rabbet edge in both directions. Subtract 1/8 inch from each measurement — the glass needs a small gap to allow for thermal expansion. (4) Cut the glass: score with a glass cutter along a straightedge in one firm pass. Snap the glass by pressing down on one side with the score line over the edge of a table or a dowel. (5) Wear cut-resistant gloves throughout.

How do I replace the screen in a storm window?

Screen replacement procedure: (1) Remove the screen panel from the window track. Lay it flat. (2) Find the spline — the narrow rubber or vinyl rope pressed into the channel around the frame perimeter that holds the screen fabric in place. Use a flathead screwdriver or the pointed end of a spline roller tool to pry up one corner of the spline. Pull it out around the perimeter. (3) Remove the old screen fabric. (4) Cut new screen fabric 1 inch larger than the frame opening on all sides. Fiberglass screen is easier to work with than aluminum; aluminum is more durable. (5) Lay the new screen over the frame, centering it. Starting at one corner, use the convex wheel of the spline roller to press the screen into the channel groove. Work along one full side, then the opposite side (to keep the screen taut), then the remaining two sides. (6) Press the new spline into the channel over the screen using the concave wheel of the spline roller. Work one side at a time. Keep tension on the screen to prevent wrinkles. (7) Trim the excess screen with a utility knife held at a slight angle against the outside edge of the spline channel.

Why does my storm window fog up or have condensation between the panes?

Condensation between a storm window and the primary window occurs when warm, moist indoor air infiltrates past the primary window (inner window) and contacts the cold glass of the storm window. This is normal and expected under certain conditions — it does not mean the storm window is defective. The solution is to reduce air infiltration at the primary (interior) window, not the storm window. (1) Weatherstrip the interior window more thoroughly — the primary window should be the main air barrier. (2) Check that the storm window itself does not have a tight air seal at the top — most storm windows are designed with a small intentional gap or weep holes at the bottom to allow some pressure equalization and prevent excessive moisture buildup. Do not seal storm windows completely airtight. (3) If moisture is trapped inside the storm window panel itself (two-pane insulated glass unit that has failed its seal), treat it as a foggy double-pane IGU — replace the glass unit.

How do I fix a storm window that will not stay in the track or keeps falling out?

Storm windows fall out of tracks for three reasons: (1) Worn or missing keepers (clips): Most storm window panels have small spring-loaded clips or keepers on the sides that press against the track and hold the panel in place. These keepers wear out or break. Replacement keepers are available at hardware stores — match the style (pile-type vs. spring-type). Squeeze the keeper with pliers to increase its grip or replace it entirely. (2) Bent track: The aluminum track channel is bent inward, preventing the panel from sliding or causing it to pop out. Use a putty knife or flat bar to gently straighten the track channel. Work gradually — aluminum bends back easily but also kinks. (3) Oversized panel: If the storm window has warped or the opening has settled, the panel may no longer fit the track properly. A panel that is too snug can be reduced by filing the edge channels slightly with a fine file. A panel that is loose needs shimming with weatherstripping or new keeper clips with more grip.

How often should storm window weatherstripping be replaced?

Storm window weatherstripping lifespan by type: (1) Foam tape (closed-cell adhesive foam): Compresses and loses resilience after 3–5 years, especially in climates with large temperature swings. Replace when it no longer springs back when pressed. (2) Pile weatherstripping (fuzzy pile in a carrier strip — the most common type on triple-track windows): Lasts 7–15 years in typical use. Replace when the pile fibers are matted flat, missing in sections, or when you can feel air movement past a closed panel. (3) Rubber or vinyl blade seal (on some premium storm windows): Lasts 10–20 years. Replace when the blade has lost its shape or has cracks. Signs that weatherstripping needs replacement: visible light around a closed panel, noticeable drafts when standing near the window in winter, increased condensation between storm and primary window (indicating air infiltration), or the panel does not feel snug when in the closed position.

To fix a storm window: (1) Cracked glass — remove the panel, press out the old glass, cut new glass 1/8 inch smaller than the opening, bed it in glazing compound, and secure with glazier’s points. (2) Torn screen — roll out the old spline and screen, cut new screen material 1 inch larger than the frame, press it in with a new spline using a rolling tool.

Storm windows are one of the most cost-effective energy upgrades for older homes — a well-functioning storm window can reduce heat loss through a single-pane window by up to 50%. Keeping them in repair is straightforward once you know how they are assembled.

What You Need

Most storm window repairs require only one or two items from this list. Having them all on hand means you can address whatever you find when you take the panels down.

Step 1: Remove the Storm Window Panels

Safe, controlled panel removal is the first step for any storm window repair. Forcing panels can bend tracks and break glass.

Triple-track windows:

  • Raise the bottom glass panel to the top of its track. It will lock in the open position.
  • Slide the screen panel down to its lowest position.
  • To remove a panel: lift it straight up until the bottom clears the track, then angle the bottom outward and lower it out. The spring tension of the keepers holds panels in — lift firmly.
  • Label each panel with masking tape (top glass, bottom glass, screen, left/right) before removing. Storm window panels from the same opening are not always interchangeable in size.

Two-track windows:

  • Most two-track storm panels lift straight up and out of the track channel. Some have a lift tab or lever at the bottom rail — press it to disengage the keeper before lifting.

Wood frame storm windows (exterior mounted):

  • These are typically held by hook-and-eye hardware at the top and lift off. Have a helper when removing large panels — they are heavy.

Lay panels flat on a padded surface (blankets on a workbench) for repair. Never lean a glass panel unsupported on its edge.

Step 2: Replace a Cracked or Broken Glass Panel

Assess first: A single crack that does not reach the edge of the panel can sometimes be stabilized with clear window repair tape temporarily, but replacement is the correct long-term fix. A panel with multiple cracks or a missing section must be replaced.

Aluminum frame panel (rubber gasket style):

  1. Lay the panel flat. Find the corner keys — small plastic or metal connectors at each corner where the aluminum extrusions join. They are accessible by looking at the corner on the exterior of the frame. Use a flathead screwdriver to pop the corner key out.

  2. With one corner key removed, the frame can be slid apart — pull the two frame sections at that corner away from each other. The rubber glazing channel (a U-shaped gasket running around the glass edge) will come with the glass.

  3. Pull the glazing channel off the old glass. Inspect it — if the rubber is cracked, brittle, or compressed flat, replace it with new glazing channel of the same size (sold by the foot at glass shops).

  4. Measure the glass opening and have new glass cut at a glass shop or home center (most will cut to size for a small fee). The glass should be 1/8 inch smaller than the opening in each direction.

  5. Slide the glazing channel onto the new glass around all four edges, mitering the corners (45-degree cuts at each corner where the channel wraps).

  6. Reassemble the frame around the new glass-and-channel assembly. Snap the corner keys back in.

Wood frame panel (glazing compound style):

  1. Wear cut-resistant gloves. Remove the broken glass — use a heat gun on low to soften old glazing compound if needed. Remove old glazier’s points (small metal triangles) with needle-nose pliers.

  2. Clean the rabbet (the groove the glass sits in) of all old glazing compound and paint debris.

  3. Apply a thin bed of fresh glazing compound in the rabbet — this cushions the glass and seals the back edge.

  4. Set the new glass into the compound bed. Press firmly.

  5. Install new glazier’s points every 6–8 inches around the perimeter by pressing them into the wood with a putty knife.

  6. Apply glazing compound around the perimeter, tooling it into a beveled triangle that sheds water away from the glass edge. Smooth with a putty knife wetted with mineral spirits.

  7. Allow compound to skin over (24–48 hours) before priming and painting.

Step 3: Replace Torn or Damaged Screen

Screen replacement is the most common storm window repair and one of the most satisfying to do yourself.

  1. Remove the screen panel and lay it flat.

  2. Remove the spline: Use a flathead screwdriver or the pointed end of the spline roller to pry up one corner of the rubber or vinyl spline (the round cord pressed into the channel holding the screen). Pull the spline out all the way around. Discard it — old spline is usually too compressed to reuse.

  3. Remove the old screen: Lift and discard.

  4. Clean the channel: Use a stiff brush or vacuum to remove debris from the spline channel groove.

  5. Cut new screen: Unroll the new screen material over the frame. Cut it 1 inch larger than the frame opening on all four sides. Fiberglass screen is recommended for most applications — it is easier to work with than aluminum, does not crease as easily, and does not oxidize.

  6. Lay the screen over the frame: Align it so the weave is square to the frame (not on a diagonal, which causes waves). Tape two corners temporarily to hold it in position while you work.

  7. Install the screen using the spline roller: Working on one long side first, place the new spline over the screen where the channel is. Using the convex wheel of the spline roller, press the screen and spline firmly into the channel. Work from the center of the side toward the corners — do not start at the corner or the screen will wrinkle.

  8. Move to the opposite long side: Pull the screen taut across the frame (not forcefully stretched, just snug) and repeat the spline-pressing process on the second long side.

  9. Complete the two short sides: Press the spline on the remaining two sides. Trim the corners of screen material if they bunch.

  10. Trim the excess screen: Hold a utility knife at about 30 degrees to the frame and run it along the outer edge of the spline channel. Cut in one smooth motion. The blade should cut the screen flush with the edge of the channel.

  11. Inspect for wrinkles — any wrinkle that will bother you needs to be re-done on the affected side. It is easier to redo one side now than to live with a wavy screen.

Step 4: Replace Worn Weatherstripping

Storm window weatherstripping is what makes the panel seal against the frame when closed. Worn weatherstripping allows cold air infiltration and negates much of the storm window’s benefit.

Pile weatherstripping (triple-track aluminum windows):

Pile weatherstripping is the fuzzy strip in a carrier that presses against the panel edges in the track channels. It is the most common type on aluminum triple-track windows.

  1. Remove the old pile strip by pulling it out of its carrier groove. On some windows, the carrier snaps in; on others it is screwed in.
  2. Cut the new pile strip to length with scissors.
  3. Press the new strip firmly into the carrier channel. It should grip without adhesive. If it does not stay seated, a small amount of contact cement in the channel will hold it.

Foam tape weatherstripping (perimeter sealing on wood storm windows):

  1. Remove all traces of old foam tape — it is adhesive-backed and leaves a residue that must be cleaned off before new tape will adhere. Use mineral spirits or adhesive remover and a scraper.
  2. Clean and dry the surface thoroughly.
  3. Apply new closed-cell foam tape to the same locations. Press it firmly into place. Allow the adhesive to bond for 30 minutes before closing the window.

Step 5: Fix Stuck or Broken Hardware

Stuck lift rail or slide panel: The most common cause is corrosion in the aluminum track channel. Apply a penetrating lubricant (such as a silicone spray or dry PTFE spray) to the track. Avoid petroleum-based lubricants — they attract dirt. Work the panel back and forth to distribute the lubricant. If the track is visibly bent inward, carefully pry it open with a putty knife.

Broken latch (closing hardware): Storm window latches are small die-cast mechanisms that engage a strike on the primary window frame. They break because they are brittle zinc alloy (pot metal). Replacement latches are sold at hardware stores and window supply houses — bring the old latch to match the mounting hole pattern. Remove the two mounting screws, swap the latch body, and reinstall.

Loose or bent keeper clips: The keeper clips on the sides of sliding panels grip the track edges and hold the panel in position. Bent keepers can be squeezed with pliers to restore tension. Broken keepers must be replaced — they are slid onto the panel edge without screws.

Reinstalling and Seasonal Maintenance

When reinstalling panels after repair:

  • Clean the track channels with a damp cloth before sliding panels in.
  • Apply a light coat of silicone spray to the track channels — this helps panels slide smoothly and prevents future corrosion.
  • Verify each panel sits snugly in its track and engages its keeper clips.
  • Check that weep holes at the bottom of the outer storm frame are clear — these drain any water that gets behind the storm panel.

Seasonal rotation schedule (two-track windows):

  • Fall: Install glass panels, store screen panels in a dry location (wrapped in cardboard to prevent scratching).
  • Spring: Swap glass for screen panels.
  • Label panels and store them flat or vertically against a wall — never stack glass panels horizontally without padding between them.
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  1. Identify the problem type

    Inspect each storm window: cracked or broken glass (visible fracture); torn or holes in the screen (visible damage to the mesh); frame that does not close or seal fully (bent frame, missing hardware, or compressed weatherstripping); lift hardware broken or stuck (the clips, latches, or lift rails that hold the panel in position). Each failure has a different repair — diagnose before ordering parts.

  2. Replace a cracked glass pane

    Measure the glass opening (frame rabbet) width and height. Order single-strength glass from a glass shop cut 1/8 inch smaller than the frame opening on each dimension. Remove the storm panel from the window. Pry or unscrew the retaining strips (the thin metal strips holding the glass in the frame). Remove the broken glass with gloves. Install the new glass in the frame, press the retaining strips back into the groove, and bend them down with a putty knife or glazing tool to hold the glass. Apply glazing compound around the perimeter if needed.

  3. Repair or replace a torn screen

    Small holes (under 1 inch): apply a patch of matching screen mesh with a self-adhesive screen patch kit. For tears over 1 inch: replace the full screen panel. Remove the frame, pry out the spline (the rubber cord holding the mesh in the frame groove), and pull out the old screen. Cut new fiberglass or aluminum screen 2 inches larger than the frame. Lay the screen over the frame and use a screen roller to press the spline and screen into the groove, starting with two opposite sides. Trim excess with a utility knife.

  4. Fix weatherstripping and sealing

    Storm window weatherstripping is a foam or pile strip that compresses when the panel closes to form an airtight seal. Compressed or missing weatherstripping allows cold air infiltration. Pull the old foam or pile strip from its channel. Press new matching weatherstripping (foam tape or pile strip in the correct width) into the channel — it is usually self-adhesive or presses into a retaining slot. Also inspect the caulk joint between the storm window frame and the exterior window casing — reapply silicone caulk to any gaps.

  5. Fix stuck or broken lift hardware

    Storm window panels use lift rails, flip latches, or tilt-in releases to lock into position. A stuck latch is usually debris or paint buildup — clean with a stiff brush and lubricate with silicone spray. A broken latch clip or rail: identify the storm window brand (often stamped in the frame) and order replacement hardware. Most hardware is universal — bring the old piece to a hardware store or search by storm window type (single, double, triple track) for matching replacement clips or rails.

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