How to replace a window seal

Updated February 21, 2017

Windows play a major role in how energy-efficient a home can be. Sealing the windows helps keep out water and drafts. If the seals on a window are cracked or broken, heat can be lost and drafts can be let in. Broken window seals can also cause window fogging or condensation. Replacing window seals, also called window glazing, is typically performed when the window glass is being replaced. Once the new glass has been put in, window-glazing sealant is applied. Repairing window seals can be a messy and time-consuming process, but it is possible to perform this task on your own, especially with new products such as caulk-like window glazing.

Remove old putty and sealant from the window where the glass meets the window framework. Use a putty knife

Replace the window glass if damaged with spots and condensation.

Insert the tube of window-glazing caulk sealant into the caulking gun. Trim the tip off the glazing caulk. Pump the handle of the caulking gun until the sealant tube has been punctured and is ready to be dispensed.

Apply the window-glazing caulk material around the outside perimeter of the window pane.

Press caulk into the crack where the glass and wood meet. Use the putty knife to fill the crack completely.

Repeat steps to seal the inside of the window, as well.

Things You'll Need

  • Putty knife
  • Glass
  • Glazing (caulk-like) compound in tube
  • Caulking gun
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About the Author

Amanda Ballard Coates is a Certified Professional Coder (CPC) and a member of the American Association of Professional Coders. She is also a freelance writer and photographer. She writes mostly nonfiction and has been published on several informative websites. Ballard Coates' writing has been published on websites such as,, and