How to Repair a Broken Window Seal

Windows that have a broken seal need to be resealed

Windows that are installed in a home typically have a bead of caulk around the side of the window to seal any air gaps. Drafts can occur when the seal on a window goes bad or begins to deteriorate over time. When this happens you will need to find where the draft is occurring and then make the necessary repairs to fix the problem. You can repair a broken window seal by applying new caulking to reseal the window.

Things You'll Need

• Ruler
• Tape measure
• Utility knife
• Needle nosed pliers
• Caulk
• Nail
• Caulk gun
• Trim pieces
• Finish nails
• Nail gun

Instructions

1. Examine the window frame and jamb and look for seams or gaps that indicate that the seal has broken on the window.

2. Determine the width of the seam or gap by measuring with a ruler or tape measure. If the gap is larger than 7/8 inch, fill strips will need to be placed in the gap.

3. Measure and cut the fill strips to the height and width of the gap, on the side of the window, with the utility knife. Insert the fill strips into the side of the window to narrow the gap.

4. Cut any caulking, if there are any seams or cracks that you can see, with the utility knife. Pull out the old caulking by grabbing onto it with the needle nosed pliers.

5. Cut the end off a tube of caulking with the utility knife. Puncture the seal on the inside of the tube with the nail. Insert the tube into a caulk gun and then press the trigger to set the push plate.

6. Set the end of the tub of caulk at the top edge of the side of the window. Press the trigger and apply a single bead of caulk down the side of the window. Dip your finger in water and then run your finger down the bead to smooth it out.

7. Apply pieces of exterior trim to cover the side of the window. Secure trim pieces with finish nails using the nail gun.

Tips & Warnings

• Do not leave any gaps or voids when applying a new bead of caulk.

References

• HandyAmerican.com: Proper Caulking
• Simple Home Repairs: Caulking and Insulation

Resources

• Read this Article in Spanish