In the world of energy efficiency, the humble tube of caulk is a mighty giant.
If installed properly, caulk can make a major difference in your comfort and energy savings over the cold weather months. Caulk is certainly more affordable than, say, new storm windows or a new high-efficiency furnace. Those can be great investments for a home, but it takes a long time to recoup the initial costs through energy savings.
Caulk around windows and exterior doors does a great job of minimizing cold air infiltration, which makes a room or house feel chillier than it actually is. With proper caulking, you can turn down the thermostat and save energy dollars.
Caulk also prevents water from working its way into your home’s shell, where it can rot the wood and stain drywall and plaster.
The key to caulk’s effectiveness is proper application. You don’t want to apply caulk outdoors when it’s too warm (above 85 degrees) or too cool (below 40 degrees). Such temperatures will adversely affect the caulk and how it bonds to surfaces of your home.
In addition, you shouldn’t apply new caulk when rain is expected in the next 12 hours.
Thus, your best bet is to install caulk on a cool, dry late summer or early fall day.
If you have an older house with lots of windows to caulk, give yourself an entire day for the job. You’ll spend lots of time just moving a ladder from place to place, especially with second-floor windows.
Where should you apply the caulk? Typically, around the perimeter of every door and window, where the outermost frame of the window or door meets the building.
Of course, you’ll need a caulk gun and at least one tube of fresh caulk, which now is usually acrylic- or latex-based. It comes in a range of grades and colors, including clear.
The first step is to examine the existing caulk. If it’s dry and brittle, chip it away with a paint scraper or putty knife and then brush away any debris. (If there are gaps larger than a half-inch or so, plug them with a spray-in foam rather than caulk.)
Next, cut the nozzle on the caulk tube at a 45 degree angle and deep enough so that when you squeeze the trigger on the caulk gun, you get a bead of caulk about one-fourth-inch thick–about what comes out of your toothpaste tube.
Apply a couple of test beads in an unnoticeable area. Notice how quickly the caulk comes out of the gun when you squeeze the trigger and how quickly it stops when you pull the plunger out of the back of the caulking gun.
When applying the caulk, hold the gun at the same 45 degree angle as the cut in the nozzle. Slowly squeeze the trigger and pull the gun towards you.
You can also smooth down the bead of caulk with a wet finger to make it less noticeable. Have lots of damp rags on hand for cleanup.
Don’t caulk only the outside of windows, but the inside of storm windows as well. Draw a smaller bead than what you applied outside to the joint where the backside of the storm window frame meets the inside well of the window. Again, even if there is no visible gap, seal the joint to prevent air infiltration.
At the bottom of the storm window, avoid caulking the weep holes, which allow rainwater to run out through the bottom of the storm window frame.
In addition to tube caulk, you can also purchase pre-formed pieces of rope caulk, which is designed to be unspooled and pressed in place by hand. Obviously, applying rope caulk is much more time-consuming to apply and more expensive than tube caulk.
When you’re finished caulking, you can paint it if it is noticeable.
Come winter, you’ll reap the benefits of your work. On cold days, you can instantly feel the difference between a window that’s sealed with caulk and one that’s not.
And, you can start dialing down the furnace thermostat to save energy dollars.
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Got a question about home energy or home environmental issues? Write to Energy Q&A, Chicago Tribune, Your Place section, 435 N. Michigan Ave., 4th Floor, Chicago, Ill. 60611. Or you can e-mail energy qa@aol.com. Questions will be answered only through the column.
