How to Repair Broken Window Glass in a Wooden Window (the Easy Way)

By thewriteDuffy •  Updated: 05/08/24 •  5 min read


If your kid’s street hockey game seemed harmless enough until a puck came crashing through the living room window (Score!), don’t worry, you can DIY a window repair.

While having a glass repair service fix the damage can be expensive, it’s a relatively simple and cheap do-it-yourself job, even for a first-timer. Think of glass repair as one of those little life skills you’ll use time and again especially if your kid’s shot doesn’t improve.

Step One: Assess if DIY is the Right Choice

You can replace the glass in a double-hung window for about a third of the cost a professional would charge.

The only time we’d hire a pro for this kind of repair is if the sash is so horribly encrusted with paint that would get destroyed by removing it, or if you have a type of modern double- or triple-glazed window where the pane is built into the frame in such a way it can’t be replaced (they are a thing now because consumerism is king; but they don’t tend to be made of wood, like we’re talking about here).

Also, if you need to replace an insulated window, a trained specialist may be the best bet for a proper installation, though it’s totally possible to replace this type of window pane as well, you’ll just need to

Step Two: Safety First (Glass Safety 101)

The importance of working safely around broken glass goes without saying. Wear heavy-duty work gloves and safety glasses to protect yourself from loose shards. Remove the window sash, and clamp it to a pair of sawhorses so it stays put while you work.

Have a trash can nearby for pieces of glass and other debris.

Step Three: Gather Your Materials

Before you begin, make sure you have the tools and materials you’ll need at the ready.

While you won’t have your replacement glass until after you can remove the old one and measure properly, make sure you have all your removal tools at the ready from the start and your primer so that you can have the wood primed and ready to go for when you have your replacement glass in hand.

Removal and Priming Steps

Replacement Steps

Step Four: Remove the Broken Glass

Remove the broken glass. Carefully remove as much of the broken glass as you can with your hands. You can use pliers to remove small, stubborn shards. Wrap the broken glass in newspaper and tape it shut before putting it out with the trash.

Step Five: Remove the Glazing Compound

There are a couple of ways to remove glazing compound also known as putty from the rabbet (which is the recessed ledge in the window sash the glass pane sits on). First, you can try prying it off the sash with a scraper or a stiff putty knife, however, the putty may be too hard to do this if your window is older.

Taking care not to gouge the wood, you also can try using a chisel to remove the compound from the window. Beforehand, score the compound well by running a utility knife along a metal straightedge where the compound meets the wood. Keep in mind, though, that wood is softer than hardened putty and easily damaged by an errant scrape from a sharp knife.

For either method, you may find it helpful to soften the putty with a heat gun (professional glaziers use expensive heating irons). Just be careful too much heat may damage the wood and create more repair work.

If you don’t have a heat gun (or good hairdryer) you can also try linseed oil to help soften it up.

Step Six: Remove the Glazing Points

Once you’ve removed the old glazing compound, use long-nosed pliers to pull the glazing points and any other debris from the rabbet.

Step Seven: Measure for Replacement Glass

Once you’ve cleaned the area, measure the distances between the top and bottom rabbets and the two side rabbets. Measure twice, then subtract 1/8 inch from both measurements to determine the height and width of the new glass pane.

Order your glass cut to fit at a specialty glass or hardware store. For most windows larger than about two feet by two feet, order double-strength window glass.

Step Eight: Prime the Rabbet

Apply an exterior-grade primer to the rabbet. The primer will prevent the wood from absorbing the oil in the glazing compound and drying it out.

Follow the intructions on the primer, but in general, allow four to six hours for a latex primer to dry before continuing; let an oil-based primer dry overnight. Quick-drying primers are a great convenience for small projects like this.

Step Nine: Install the New Glass Pane

Apply a 1/8-inch bead of glazing compound or acrylic caulk around the rabbet’s perimeter, and press the glass pane into place to create a tight seal.

Install glazing points at 8-inch intervals around the glass. Press the tip of the glazing point into the side of the rabbet, and use a stiff putty knife or a screwdriver to wiggle the point into the wood, as shown in the animation.

Step Ten: Allow the Window to Set

thewriteDuffy

At home, April is a mom, wife, and DIY darling. Among other home projects, she helped her husband Dan renovate their 1986 bungalow and is currently designing and decorating the 2023 custom home they are building themselves. Professionally, April is a writer, author, and online marketer with 15 years of experience writing for newspapers and magazines, building online authority websites, and publishing books.