How to Caulk Windows

Tips for Caulking around Exterior Windows

By Mark J. Donovan




Appling caulk around exterior windows can help keep your home feeling more comfortable during winter months.

Caulking exterior windows can prevent drafts and heat loss, as well as save you money on your home heating bills.

Tools Required to Caulk Windows Outside

To caulk around exterior windows you will need silicone caulk, a caulk gun, a utility knife, a putty knife, a long nail, and a few moist paper towels.

Clean Exterior Window Frame Before Caulking Outside Windows

The first step in caulking windows is to clean around the exterior edges of the window making sure to remove any old dried-out caulk.

Use a putty knife and paper towels to clean the exterior window edges.

Next, insert your tube of silicone caulk into the caulk gun.

Using your utility knife cut the tip off of the caulk tube.

Make sure when you cut the tip off of the tube that you cut it at about a 45o angle, and such that the opening has a diameter that is equal to the width of the seam you are going to caulk.

Slide the long nail into the caulk tube a couple of times to break the seal within the tube.

How to Caulk Windows using Caulking Gun

Proceed to caulk the exterior window edge at a controlled and measured rate, making sure you apply even pressure to the caulking handle at all times. If you move the caulk gun too slowly you will end up applying too much caulk on the window seam.

If you move the caulk gun too quickly you will end up with an insufficient amount of caulk on the window seam.

After applying a bead of caulk to the window make sure you pull back on the caulking gun’s ratchet rod to relieve the pressure in the tube of caulk.

This will prevent excess caulk from spilling out of the tube.

Once you have caulked around the exterior window use a damp towel, a plastic spoon, or your wet finger to smooth the caulk bead into the seam.

Caulking Exterior Windows

Watch this video to learn how to caulk a window.

Allow the caulk to fully dry before applying paint.

Make sure to use the right type of caulk when caulking windows. See this article on types of caulk to learn more.


For information on Installing Replacement Windows and Interior Window Trim

  • See the Installing a New Window Ebook from HomeAdditionPlus.com.  The Installing a New Window Ebook provides easy to understand, step-by-step instructions, on how to remove an old window and install a new one. Pictures are included for every key step in the process.

Installing a New Window Ebook

  • See the Installing Interior Window Trim Ebook from HomeAdditionPlus.com.  The Installing Interior Window Trim Ebook provides easy to understand, step-by-step instructions, on how to install interior window trim around a window. Pictures are included for every key step in the process.

Installing Window Trim eBook

Related Information on How to Caulk Windows


Additional Window Installation and Maintenance Resources from Amazon.com


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