Reglazing Wood Windows - A Simple How-To

Ah, sunshine and a soft breeze coming through your window. How delightful. Well, it would be, if the breeze was actually coming through the open window, rather than the gaps around the edges. And it's not just annoying-it's also eating away at your home's energy-efficiency.


The problem is usually the caulking or putty around the glass panes, which dries and becomes brittle over time. The good news is reglazing windows isn't as scary as it seems. You just need the right tools and techniques.

Clean Up and Prep the Window

As with any project, the first priority is safety. You should wear safety glasses or goggles at all times, particularly when working with broken glass. You should also wear gloves to protect your hands. Once you've donned all your safety gear, it's time to get started.

Carefully remove any broken pieces of glass from the frame and scrape away the putty. It should lift away relatively easily, but if it doesn't, use a sharp utility knife and small scraper.

While removing the old glass and putty, you'll notice small diamond-shaped pieces of metal in the frame. Called glazing points, the factory shoots them into the wood to hold the glass in the frames. Without them, the glass would eventually fall out.

Get the Replacement Glass Ready

You can now measure the length and height of the opening. To cover yourself in case the opening isn't true, add 1/8" to each measurement to give yourself extra room.

A flat cushioned table, t-squares, oil, and cutting tools.

Next, gather all the tools and supplies you'll need to cut the glass: a flat cushioned table, t-squares, oil, and cutting tools. To make the glass easy to cut, use a very sharp cutting wheel on your glass cutter and lubricate it with machine oil.

Cut the Glass

Adjust your measurement to account for the thickness of the glass cutter

Before you start cutting, you need to decide where to cut it. Adjust your measurement to account for the thickness of the glass cutter. To get a proper measurement without marking the glass, use a steel measuring tape and move the straightedge. Now, it's time to make your cut.

For maximum control over the cutter, hold the handle between your middle and index finger. The tips of your index finger and thumb should grip the handle just above the cutting wheel.

Make sure you only score it with one even cut. If you don't, the glass will shatter or break unevenly

Start cutting at the edge, and add pressure until the wheel digs slightly into the glass. In one smooth, continuous motion, score the glass, making sure it gives off a long, even raspy sound as you cut. Make sure you only score it with one even cut. If you don't, the glass will shatter or break unevenly.

Quickly grip the glass on either side of the score mark, with your thumbs on top and your index fingers underneath. Put firm even pressure on both sides and snap the glass. Dry-fit the glass to check the fit, and then, start the next piece.

Finish Reglazing the Wood Window

In the final step, adhere the glass to the frame by applying a thin, even layer of caulking along the inside lip of the sash or muntins, and pressing the glass into it. Next, install two glazing points on each side of the pane and apply putty all the way around. Smooth out any bumps or cracks in the caulking by rubbing it lightly with your finger.

This process can be a lot of work, particularly if you're working with multiple pane windows. But increasing your home's energy efficiency without having to buy new windows can be well worth it.

And if the process seems overwhelming or you need help, you can always contact a professional.