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How to Seal a Window

Over time, wear and tear to your windows can cause them to lose their seal and become drafty. Luckily, sealing your windows is an easy task and only requires a few materials and some patience. There are several ways to seal a window and here, our experts share the most popular:

Around the Window

  1. First, determine where your draft is coming from.
  2. If it’s coming from between the glass and the stiles/rails:
    1. Remove the window.
    2. Use a putty knife to remove the old caulk.
    3. Wipe down the area with warm water and a rag to make sure all of the old caulk is gone.
    4. Once the area is dry, squeeze a bead of window caulk along the seams.
    5. Next, use a craft stick to smooth down the caulk and let it dry.
  3. If it’s coming from between the window and the frame:
    1. First, open the window and clean the area with warm water and a rag.
    2. Once the area is dry, measure the appropriate length of rope caulk.
    3. Next, put on your rubber gloves.
    4. Dip the rope caulk into warm water for a few seconds to soften it.
    5. Press the caulk into the gaps and let it dry.
  4. If it’s coming from between the frame and the wall:
    1. Locate where the window meets your home’s exterior wall.
    2. Wipe down the area with warm water and a rag.
    3. Once it’s dry, squeeze a bead of caulk along the line where the frame and wall meet.
    4. Let it dry completely.

Inside the Trim

By removing your window trim, you can do a much better job of sealing your window.

  1. First, choose whether you want to remove your interior or exterior window trim.
  2. Next, use your hammer and pry bar to remove the trim.
  3. Spray your foam sealant into the void. (Don’t worry if it overflows.)
  4. Let the foam dry completely. This will take several hours.
  5. After that, use a utility knife to cut off the excess sealant.
  6. Use your hammer and nails to replace the trim in the reverse order you removed it.

With Weatherstripping

If your window’s weatherstripping is old or damaged, it could be leading to drafts.

  1. First, remove your window.
  2. Next, locate the old weatherstripping.
    1. It will likely be a foam type that has lost its grip and is pulling away from the window frame or a rubber/vinyl type that is cracking or has lost its shape.
  3. Remove the weatherstripping by peeling it away from the frame. If it’s difficult to remove, try prying it up with a flathead screwdriver and a hammer.
  4. Once the weatherstripping is gone, wipe the area down with warm water, soap, and a rag to remove the residue.
  5. Replace the weatherstripping with the same kind that you removed.
    1. Either peel-and-stick foam weatherstripping along the frame or glue the weatherstripping down.

Tools & Materials

  • Putty knife
  • Warm water, rag
  • Window or rope caulk
  • Craft stick
  • Rubber gloves
  • Pry bar
  • Hammer
  • Foam sealant
  • Utility knife
  • Nails
  • Flathead screwdriver
  • Soap

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