How to Replace Window Glass: From Crack to Caulk in a Few Simple Steps

A line drive shot through the window pane. An errant bird trying to dive bomb your casement windows. When faced with any of these natural glass disasters you'll need to know how to replace window glass. And because the process is fairly simple, there's certainly no need to shell out big bucks for a contractor to do the work. Here's how.

How to Replace Window Glass: The Prep Work

The first few steps are critical. Use protective gloves to remove broken shards and a broom to sweep up shattered pieces. These two safety measures simply can not be understated.

Stripping the Glazing Compound

Using a putty knife, remove the glazing compound from the perimeter of the frame. Failure to do so will result in hardened compound that is nearly impossible to work around. Use long-nosed pliers to remove glazing points.

Preparing the Wood for Installation

Brush on a liberal coat of fast-drying paint primer to exposed wood pieces. This will create a seal that prevents accumulation and absorption of glazing oils.

Measuring the New Window Insert

Measure the opening precisely and take those figures to a window specialist. Shoot for a replacement piece 1/8 inch smaller than the measurements you took in the beginning. You can cut the new window yourself using a glass cutter and the edge of a table. Shear straight lines and then gently break the pieces. Cleaning windows are a good idea at this point so you'll have a better view of the insert.

The Finishing Touches

Use caulk or a glazing compound to apply an airtight seal that will hold the new insert. Apply glazing points about 2 inches from the corner with 8 inches in between each point. Press the insert gently into place, removing any excess caulking and allow to dry.