Replacing Window Glass

Steps for Re-glazing a broken Window

By Mark J. Donovan

If you have an old window that has had its glass broken you can repair it yourself using a few simple household tools. Tools required to replace broken window glass include a: putty knife, caulking gun, hair dryer, needle nose pliers, standard pliers, and sandpaper. For materials, you will need a piece of replacement glass, glazing compound, glazing points, caulk, wood sealer and paint.

In addition, make sure to have a pair of safety glasses and work gloves as working with glass is dangerous. Also, it is best to remove the window sash with the broken glass from the window frame and to work with it on a large flat surface.

To begin the process of replacing window glass put on your safety glasses and work gloves, and remove any broken glass remnants from the window sash. The pliers can help to remove any smaller shards of glass from the window sash.

Then, using your putty knife, remove the old glazing compound from the window sash. Work your way around the window sash to slowly and carefully remove all remains of the old glazing compound. Work in either a clockwise or counterclockwise rotation around the window sash to ensure you get it all out. To help in the process of removing the old glazing compound use a hair dryer to heat up the glazing compound in the specific area you are working to remove it from the sash. The hair dryer will soften the glazing compound which will help make it easier to scrape out with your putty knife. Continue to use the hair dryer to warm the old glazing compound as you work your way around the window sash.

As you remove the old glazing compound also use your needle nose pliers to remove any glazing points that are still fastened into the window sash and old glazing compound.

Once you’ve removed all the old glazing compound and glazing points use your sandpaper to smooth down the sash area where the glazing compound was, and any old residual paint.

Next apply a wood sealer to the window sash, where the old glazing compound was, to protect the wood.

Then insert your piece of replacement window glass into the window sash being careful not to break it in the process. When you ordered the replacement glass you should have ordered it about 1/8th inch narrower and taller than the actual dimensions of the window sash.

After inserting the new piece of glass into the window sash, fasten glazing points every few inches around the perimeter of the window sash. Also make sure to install two glazing points near each of the four corners of the replacement glass window. Again, be careful not to break the glass while installing the glazing points.

Once you’ve completed installing the glazing points, apply a bead of new glazing compound around the perimeter of the window sash and along the surface of the replacement glass. For best success roll out a string of glazing compound approximately ¼ inch in diameter. Then use your putty knife and fingers to work it into place around the window sash edges.

How to Install a Window Ebook

After you have applied the new glazing compound to the window sash, use a lightly damp rag and your finger to smooth out the glazing compound and to clean the replacement glass surface.

Allow the glazing compound to set up overnight before painting the window sash.

Finally, after the paint has had sufficient time to dry, reinsert the repaired window back into the window frame to complete the project.

For more information on Installing Replacement Windows and Interior Window Trim

  • See the Installing a New Window Ebook from  The Installing a New Window Ebook provides easy to understand, step-by-step instructions, on how to remove an old window and install a new one. Pictures are included for every key step in the process.
  • See the Installing Interior Window Trim Ebook from  The Installing Interior Window Trim Ebook provides easy to understand, step-by-step instructions, on how to install interior window trim around a window. Pictures are included for every key step in the process.

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Additional Window Installation and Maintenance Resources from

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