Caulking windows adds both the finished look and also the insulation you need to enjoy your home free of drafts and leaks. A task that may seem simple at first caulking, windows, and similar home improvements require some research and practice before getting that professional look. The act of lining your window with a narrow strip of continuous caulk is called running a bead. Learn how you can create a beautiful and efficient caulk finish.

All Caulking is Not Equal

You’ll want to know what kind of window installation and climate area you are working with before applying caulk. If you go to the home improvement store, you’ll notice a very large selection of caulk-like tubes. Make sure you carefully read the labels before selecting the right item. Some of the tubes will be more of a glue and others will be a more flexible rubber-like seal. You will likely choose between silicon and latex options, in addition to some special applications like polyurethane.

For example, a humid room like a bathroom, you’ll want to choose waterproof and mold-resistant caulking. Look for an interior caulking, and then find a color complementary to your windows and walls, or even use a clear sealant. Regular interior windows such as the living room or bedroom may look best with an interior paintable caulk, such as a paintable latex to match your decor. Exterior caulk is designed to stand up to harsh UV rays, rain, snow, and fluctuating temperature. Make sure you don’t accidentally grab an indoor variety for an exterior application. For specialty sidings like masonry siding in a brick home or some basement windows, you’ll need a specialty caulking to adhere to the surface such as an acrylic urethane.

Prepare the Area Before Caulking

Unfortunately, you can’t simply walk up to a window and begin caulking. First, you will need to prepare the area. Remove all of the old caulking if this is a window replacement. In new installations, you’ll want to make sure the area is clean, dry, and free of any debris. If you have an extremely slippery surface, you may consider priming the area (like you would in painting) before you begin. You’ll also want to check the weather before you begin any external applications. The temperature should be on the moderate side, but no colder than 40 degrees and no hotter than 90. Try to choose a day where it will be drier, and not rain or snow. In poor conditions, caulking may take as long as 24 hours to dry.

Assemble the correct tools before you start the job. Gather your caulk tubes, it’s always best to have more than one as a backup unless the job is extremely small. You will also need a caulking gun. You can choose between a ratcheting gun or a somewhat easier thumb-release for most home improvement jobs. Additional tools and materials to gather include:

• Utility Knife
• Wire Brush
• Painter’s Tape
• Caulk Finishing Tool
• Caulk Remover Solution
• Cleaning Cloths
• Mineral Spirits (used for cleanup)
• Rubbing Alcohol

Remember that like glue or paint, excess material can damage clothing, carpet, or furniture.

Tips for Caulking Application

The next steps to begin include opening the tube of caulk. Cut the tip off the tube — but don’t cut too far. The larger the cut, the larger the bead of caulk. Try a conservative cut and then test a strip first, since you can always cut more later. Use your hands to apply a test strip of caulk on practice material. Your dominant hand should control the bead, guided by your other hand as support. You’ll likely notice some wobbling or uneven pressure in your first attempt, thus the need for practice. As you gain confidence and move to the actual windows, you can run a continuous strip from side to side, exerting a regular speed and pressure. For medium or larger size windows, you may also begin at each end and create 2 strips that meet in the middle. Follow the smoothest edge of your window if there are bumps or uneven siding in this area.

If you still struggle despite your best efforts, you can also use painters tape to ensure a more even application. Tape off the window 1/8″ away from the seam itself, then smooth before removing the tape for a 1/4″ application. After you’ve applied the caulking strip, you’ll want to smooth this with a wetted finger or application tool. Smooth your caulking in steps, or else you’ll create an excess of material to clean as you go. Start at the bottom and smooth 6 inch sections. Then move section by section to the top.

And one final tip – use caulking as intended. For other fixes, check with your local store for the needed fillers and glues.