DIY: Replace Broken Windows in Wooden Frames

Save yourself money by doing your own glazing. This easy-to-follow guide will help you do a professional job. Please take care to protect yourself from the hazards posed by working with glass.

Your tools:

• Tape Measure
• Hammer
• Putty Knife  
• Water Bucket
• Goggles
• Gloves
• Hacking Knife
• Chisel

1. Measuring for new glass

Measure the rebate (the area into which the glass will fit, including the groove in the frame) both horizontally and vertically. Double-check for squareness by measuring the diagonals, which should be equal. If your frame is not square, cut a piece of stiff cardboard to the exact size of the rebate. The glazier will use this as a template for cutting the glass to the correct size, allowing for the necessary clearance.

2. Hacking out the broken glass

The process of cleaning out an old rebate to take new glass is known as hacking out. Wear protective gloves and goggles to remove segments of glass from the broken window. Use a hacking knife to hack out old putty and glass. Carefully pull out panel pins with pliers or pincers. Clean out the rebate using a dusting brush.

3. Apply putty on the inside

Never apply putty to bare wood. Use a primer to prevent wood sucking oil from the putty. When the primer is dry, knead the putty into a workable plastic state by squeezing it in your hands for a few minutes. Squeeze the putty roughly into the rebate, using your thumb and forefinger.

4. Fit glass

Working from the outside, put the pane of glass in the bedding putty and press it gently into place. Do not press the centre of the pane as this may cause it to crack. Tap in panel pins until they are flush with the glass, using a hammer. The hammer head should slide gently against the glass to secure the sprigs. (Do not aim blows as if you were knocking in a nail.)

5. Apply putty on the outside

Fill the rebate on the outside of the window with putty, pressing it in with your thumb and forefinger. Use a putty knife to obtain a smooth finish, matching the angle on the surrounding panes of the glass. Form the putty into a neat mitred joint at the corners of the frame. To prevent the knife from sticking, keep dipping it into a jar of water. This smooths the putty and seals it onto the glass. Cut excess putty away from inside the window using the putty knife, then brush down with a dry brush to seal.

6. Finished glass

Showing glass rebate, putty bedding, mitred putty edge and panel pins or sprigs holding the glass in place.