How to Save Energy by Caulking Windows

Window Caulking Improves Comfort and Saves Energy

By Mark J. Donovan

Old or no window caulking around windows is a major contributor to home energy loss. You can dramatically save on home energy bills by caulking around your windows. Caulking windows prevents warm air from escaping your home during the winter. Likewise, during the summer window caulking prevents air conditioned air from escaping your home.

The lack of window caulking can also contribute to water infiltration, which can lead to both cosmetic and structural damage to the interior and exterior of your home. Applying window caulk is inexpensive and easy to do.

When buying window caulk it’s important to make sure to purchase exterior grade window caulk that is paintable or clear. Preferably buy window caulking that partially contains silicone so that it is flexible and can expand and contract with the window as the outside air temperature changes. Common caulking types used around windows include silicone with latex caulking, acrylic with silicone caulking and 100% pure silicone caulking. All of these products have their pros and cons but in general they are extremely durable and resilient and can hold up for many years.

To apply window caulk all you need is a caulking gun, carpenters knife, ladder, long thin screwdriver, putty knife, a roll of paper towels, and a small bucket of water.

Before applying window caulk wash down the windows and siding so that they are free from any dust, debris and oil. This way you can ensure a good bond between the window trim and caulking.

Next, use your carpenters knife and cut the tip of the caulking tube off at a 45 degree angle so that you can produce a ¼ inch thick caulk bead. Then use your long thin screwdriver to break the seal inside the caulking tube.

Next install the caulking tube into the caulking gun and pull the trigger until you feel just the slightest of pressure. You may need to adjust the rod on the caulking gun, depending upon the type you have, to engage the ratcheting mechanism.

Then begin applying the window caulk to the side of the window frame holding the caulking gun at about a 45 degree angle. Work from the top of the window and then down the sides. Finally apply window caulking underneath the bottom of the window. Make sure not to run the caulking gun too fast around the window to prevent caulking voids or thin stringy beads. On the other hand, don’t move the caulking gun so slowly that you end up getting too thick of a bead. After applying a bead of caulk remove the trigger pressure from the caulking gun to stop the flow of caulk out of the tube. Caulking Exterior Windows

After applying caulk to each side of the window you may want to use your finger to press the caulk in and to reduce the size of the caulk bead. A moist paper towel also is helpful during this phase of the window caulking project. If you can avoid having to finger tool the caulk altogether even better, however this usually requires some practice with the caulking gun and getting just the right size caulk bead.

In the event you have wide seams to caulk, e.g. approximately ¼ to ½ inch in width, use backer rod to fill the voids prior to applying the window caulk. Use your screwdriver or a putty knife to push the backer rod into the wide seams.

So if your windows are in need of caulking grab your tools and a few tubes of window caulking and begin saving energy in your home.

For more information on Installing Replacement Windows and Interior Window Trim

  • See the Installing a New Window Ebook from  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.
  • See the Installing Interior Window Trim Ebook from  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.

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