To repair a broken window, first make it safe: wear gloves and eye protection, tape or cover the glass, and remove loose shards. For a single-pane wood window, chip out the old glazing putty and points, measure the opening and order glass ⅛ inch smaller each way, bed it in a thin layer of putty, push in new glazing points every 6–8 inches, and finish with a beveled bead of glazing compound. Double-pane (insulated) glass usually needs a new sealed unit or sash from a glass shop.
Safety: Broken glass cuts deeply. Wear heavy work gloves, long sleeves and safety glasses; work from the top shards down; and put large pieces in a cardboard box taped shut before disposal. If your home was built before 1978, the old paint and putty may contain lead—mist with water before scraping, avoid dry sanding or heat above 1,100°F, and clean up with a HEPA vacuum and wet wipes. Keep kids and pets out of the area.
Temporary Fixes for a Broken Window
- Small crack: Clear packing tape on both sides, or a clear window-repair epoxy, slows the spread.
- Hole or missing glass: Cover with heavy plastic sheeting taped to the frame, or screw a piece of plywood over the opening from outside.
- Shattered pane still in place: Crisscross wide tape over the glass before removing it so it comes out in larger pieces.
Repair Options Compared
| Window type | Best fix | DIY? | Typical cost |
|---|---|---|---|
| Single pane, wood sash | Reglaze with new glass and putty | Yes | $20–$60 materials |
| Single pane, vinyl or aluminum | Replace glass held by snap-in stops or spline | Often | $30–$100 |
| Double pane (insulated) | Replace the sealed glass unit | Pro recommended | $150–$500+ |
| Rotted or broken sash | New sash or full window | Pro | $300–$1,000+ |
How to Replace a Single Pane of Glass
- Remove the sash if you can. Working flat on a table is safer and easier than on a ladder.
- Remove broken glass by rocking shards out carefully, wearing gloves.
- Remove old putty with a putty knife or chisel. Mist old paint first. A heat gun on low can soften stubborn putty, but don’t use heat on lead paint.
- Pull the old glazing points with pliers.
- Prep the rabbet. Scrape it clean, then brush on boiled linseed oil or primer so the wood doesn’t pull oil from the new putty.
- Measure and buy glass. Measure the opening width and height and subtract ⅛ inch from each. A hardware store or glass shop can cut it.
- Bed the glass. Lay a thin (about ⅛ in) bead of glazing compound in the rabbet and press the glass gently into it.
- Set glazing points every 6–8 inches, pushing them into the wood with a putty knife or point driver.
- Apply the final bead. Roll putty into a rope, press it along the edge, and drag the putty knife at an angle to form a smooth bevel.
- Let it cure, then paint. Wait the time listed on the product, then paint, lapping 1/16 inch onto the glass to seal it.
DIY vs Calling a Glass Shop
Pros
- Reglazing a single pane costs very little
- Old wood windows last for decades with care
- Glass shops cut glass to size cheaply
Cons
- Glazing putty can take days to weeks to cure
- Insulated units must be ordered to exact size
- Large or upper-story windows are risky DIY
Frequently Asked Questions
Can a cracked window be repaired without replacing the glass?
Small cracks can be stabilized with clear epoxy or tape, but that’s temporary. Cracked glass is weaker and should be replaced.
How much does it cost to fix a broken window?
DIY single-pane reglazing is often under $60. Professional glass replacement commonly runs $150–$500 depending on size and type.
Can I replace just one pane in a double-pane window?
No. Insulated glass is a sealed unit, so the whole unit is replaced. The frame can usually stay.
How long does glazing putty take to dry?
Traditional oil-based putty may need one to several weeks before painting; latex glazing compounds can often be painted in hours. Follow the label.
What kind of glass should I buy?
Match the old thickness (often ⅛ inch). Glass near doors, floors or in bathrooms may need safety (tempered) glass under building codes—ask the glass shop.
