caulking windows

Angie's How To Caulk Windows

Date Published: Dec. 18, 2014

Time: 60 Minutes

Feel a draft when you walk by the windows in your home? That extra chill in the winter or warm air seeping in during the summer can inflate energy bills. One way to keep money from whooshing out is to caulk around windows, typically done to address exterior issues.

Mark Spencer, owner of highly rated Legacy Window & Door in Westfield, Indiana, recommends silicone as a superior sealant to handle seasonal changes experienced in most homes. He says you can apply most high quality silicone products in wet and cold weather. Still, he adds, look at surface recommendations and application restrictions before purchasing caulk.

Don’t go cheap on the caulk gun either. “Plan on spending about $12 and you’ll get one that will last,” Spencer says.

Follow these steps to seal in savings, and maybe even keep some ants from marching in as well.


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Tools & Materials Needed 
Caulk — latex or silicone-based
Caulk gun
Foam paintbrush, plastic spoon or craft stick (optional)
Painter’s tape (optional)
Paper towels
Putty knife or scraper
Utility knife
Wash cloth
Wire brush
removing old caulk
1Inspect window and remove old caulk

Look to see if the window needs to be scraped, primed and painted or even replaced. If your window frames are rotting and need to be replaced, no amount of caulk will fix your problem.

Window caulk-able? Remove old caulk and paint from seams and cracks using a scraper, putty knife or utility knife. Get as close to the joint edges as possible during the removal process.

painters tape to caulk windows
2Prep the window

Take care to clean and dry all surfaces around the window where you plan to apply new sealant. Make sure surfaces are dust-free and frost-free, too. “Use a wire brush if needed. Blow out dust and other debris,” Spencer says.


Optional: Apply painter’s tape on either side of window seams you plan to caulk to serve as a guide.

3Load the caulking gun

Cut the caulking tube tip at a 45-degree angle and load it into the gun. If you haven’t caulked before, practice by drawing a bead on newspaper or another throw-away surface as you pull the gun back toward you.

caulking windows
4Caulk away

Apply the bead to the seam of the window in a steady, smooth line without lots of stops and starts. Do the same for cracks that you want to caulk.

smoothing caulk around windows
5Smooth the caulk

You can use your wet finger (if you’re OK with that) to smooth the caulk, wiping off with a paper towel. Flatten the bead and push it into the seam or crack after you apply each line. This will help seal those areas. Don’t panic if you caulk “outside the lines” — just use a damp wash cloth to fix your mistakes.


Optional: Don’t want to use your finger? Try a foam paint brush or craft stick to smooth the caulk.

caulking windows
6Let your handiwork dry

Do this for as long as recommended, according to product specifications. Don’t disturb the surface during this time, apart from removing tape if you used it. “Silicone cure time will vary, but typically the product reaches its reported functioning properties within 72 hours,” Spencer says. Some other products cure faster, within a day or so, depending on weather conditions, such as humidity.