How to Replace Broken Casement Window Glass

Lead Image for How to Replace Broken Casement Window Glass
  • 2-5 hours
  • Beginner
  • 50-300
What You'll Need
New glass
Measuring tape
Spring clips
Putty knife
Medium grit sandpaper
Clean rag
Protective overalls
Working gloves

Casement window glass is held in the frame by small wire clips or vinyl clips. Heavy rains, strong winds, or hitting them with objects using too much pressure can crack, break or shatter the glass. Inspect windows regularly and correct such faults by replacing the broken glass with new pieces. The job can be easily done at home. Find out how many windows need repairs and estimate the time required to finish the job.

Assemble Necessary Materials

If the window is located high up on the wall, prop a ladder safely and firmly. Wear strong rubber gloves while removing broken glass from the window. Collect it in a bucket and dispose of it properly.

Use a putty knife or chisel to remove the glazing compound on the window frame. Remove spring clips using pliers. Vinyl splines can be removed easily using a screwdriver.

Clean the Surface

Use a brush to remove small particles or debris of the glazing compound from the window frame. Use steel wool and sandpaper to remove the uneven finish, paint flakes or residue, and hardened dirt. Use a solvent to remove hardened paint and other residues from the frame. Use a wet and soapy rag to remove dirt and dust from the window and the opening. Rinse with a clean rag and leave the window to dry.

Measure Window Frame

Take the measurements of the window frame. Spread the tape measure from top to bottom and then take it from side to side. All four sides of the new pane should be 1/16 to 1/18 inch smaller than the frame of the window.

Use the measurement to buy a new window pane. Carry a small piece of the broken window as a sample. This makes it easy to get an exact replacement.

Prepare the Frame

Use a brush to apply paint on the frame. It is advisable to use the same type of paint applied before. To protect the window even better, use paint inhibiting primer and paint to prevent the frame from rust and corrosion. Apply two coats of primer and two coats of paint. Let each layer dry completely before applying the next one.

Apply Putty

Putty works best on steel casements. Apply putty evenly on the frame and carefully position the new glass on the frame. Press it gently until it settles in, and watch out where putty is not applied properly. Cut excess putty using a putty knife and use it to even and smooth the surface.

For wooden frames, use caulk. Install the spring clips or splines into the sash and make sure they are secure. Apply an even bead of caulk on the frame and position the glass. Smooth excess caulk and leave the caulk to dry.

After the putty or caulk has dried, paint it to have an attractive finish.