One of the most common items found in homes I inspect are windows that have caulking that is either missing or cracked. Nearly 65% of a homes energy bill is used to cool or heat the home, yet nearly half of this conditioned air leaks out of the home. Sealing your windows is an easy task to do and could save you up to $150 a year in costs.
1. Check for Leaks
The first step would be to see if you have drafts through your closed windows. You can do this by holding a lit candle around the seams of the window. If the flame bends, you may have leaks. Also, check the exterior caulking. In the summer, caulk can dry up and crack. If you see cracks and gaps, it's time to get out the caulk gun.
2. Remove Old Caulking
You can use a caulk softener if the caulk doesn't easily come off. Make sure to apply this two hours prior. Once it has set, use a putty knife and the old caulk should come off easily. You want to remove as much of the old caulk as possible to make sure the new caulk will adhere and give you a good seal.
3. Apply New Caulk
There are many different kinds of caulk, but for big and small gaps Polyurethane works great. Cut the tip of the caulk tube at a 45 degree angle to ensure the tip will fit snug into the window seam, then insert into the caulking gun. Hold the caulking gun at a 45 degree angle and apply in a smooth, slow motion. Use a wet finger to smooth out the surface to give it a clean, finished look. Allow 12-15 hours to set and your windows will be air tight for the season.
Devereaux Van Dyne, Certified Professional Home Inspector