Windows are a crucial part of any home, but they can be subjected to a lot of wear and tear. In the colder months, it’s important to take some extra steps to seal your windows and keep the warmth in. 


Caulking windows is a common DIY task that must be done properly to seal leaks and give windows a more finished look. Continue reading if you want to caulk your windows but don’t know how to.

1. Conduct Pre-Application Check-Ups

Before you start caulking windows, pre-application check-ups are essential to ensure that the process goes smoothly. 

Locate Air Draft Locations

The first thing you need to do is look for any areas on your windows with air leakage. You can do this by feeling around the window frames’ edges. 

Another way to locate air drafts is by lighting a candle and moving the flame around the window frame edges. The flame wavering means there’s moving air, indicating it for caulking. 

Check Window Surfaces

After locating the air drafts, you must clean the window surfaces to ensure that the caulk will adhere properly. During winter, check the window surfaces for any ice because you have to melt and dry the icy parts before applying caulk. 

It can form a barrier between the surface and the caulk if you don’t. 

Scrape Old Caulking

You need to scrape off any old caulk using a putty knife, stiff brush, screwdriver, or a special solvent. Applying a new caulk over an old one will affect its adherence.

2. Prepare Your Working Table And Materials

After locating where to caulk and cleaning the window surfaces, you must ensure that all your materials and working station are prepared. 

Materials You’ll Need

The following materials are essential to make caulking windows a success:

  • Wire brush
  • Caulk gun
  • Caulk finishing tool
  • Caulk and caulk remover
  • Cleaning cloths and disinfectant
  • Mineral spirits

Choose The Correct Caulk

One of the crucial decisions you have to make is choosing the right caulk for exterior and interior windows. Generally, the basic types of caulk are acrylic latex, silicone, siliconized latex, and polyurethane. 

Acrylic Latex

Acrylic latex is ideal for interior windows; it is water-based and contains fewer dangerous chemical substances. This caulk material is also easier to clean and can be painted. 

Some acrylic latex caulk also comes in pre-tinted forms to complement your existing window color schemes. However, it is not temperature or weather-resistant. 


Unlike acrylic latex, silicone is more resilient against mildew and temperature, making it ideal for bath, kitchen, and HVAC purposes. It’s also waterproof, which is ideal for sinks and tubs.

Silicone caulk can be acid-cure or neutral-cure. Acid-cure silicone is best for non-porous mediums such as glass. On the other hand, neutral-cure is ideal for plastic, wood, metal, and vinyl siding. 

Siliconized Latex

Siliconized latex is ideal for exterior windows. It works like acrylic latex but contains silane. Silanes are more resistant to weather and are more durable than acrylic latex.


Polyurethane is a powerful material for caulking because it is solvent-based; however, it can be more challenging to work with this material than silicone. This caulk material ideally bonds with common materials for housing construction. 

However, note that it can break down when exposed to harmful UV radiation. 

3. Set-Up The Caulking Tube and Gun

After choosing the appropriate caulk material to use, it’s time to set up the caulking tube in the calking gun. 

Check If Caulk Gun Is Functioning

You can check whether your caulk gun is properly functioning by testing the trigger and plunger. Do this by removing the caulk tube inside and depressing the gun’s trigger. If you can’t depress the trigger, reset it by pulling the release bar of the plunger back and then try again. 

It’s also important to test the spring of the plunger for tautness. If the spring is too loose or strained, the plunger will not be pushed with the right force. In this case, you have to replace the entire caulking gun. 

Open Your Caulk Tube

If your caulking gun has a metal prong, try to poke it into the caulk tube.

Install a new caulk tube if it’s empty or if the old caulk has hardened and dried up. If you want to cut off the tip of the tube, remember to cut only a small part of it. The larger you cut, the bigger and thicker the bead becomes. 

4. Meticulously Apply The Caulking

As you begin to apply the caulk, use both hands in controlling the caulking gun. Hold the gun and pull its trigger with your dominant hand, and support the gun’s barrel using your other hand. Ensure your wrists are always straight. Only move your body and elbows while caulking. If you bend your wrists, it can alter the caulking gun’s angle and change the appearance of the caulk. 

Apply caulk from one end, running towards the middle, and stop. Then, start caulking at the other end to meet at the middle. Doing this can result in a more uniform bead because your steady hand position is maintained. 

5. Smoothen or Flatten The Beads As Necessary

After applying the caulk, you can smoothen the beads by using a caulk applicator or your wet fingers. Smoothen the bead in the partition, and start at least six inches from the bottom part. Then move up for another six inches and begin smoothening to the bottom.

Caulk dries for hours, giving you ample time to smoothen and remove any excess caulk. 

6. Do Post-Application Check-Ups

After the caulk has dried completely, recheck the window surface whether the caulk has completely smoothened and the air drafts are completely covered. Ensure that there is no excess caulk on your window surfaces; the window edges have to be clean as well. 

7. Clean-Up

When the windows have been properly caulked, it’s time to clean up. Wipe off the caulk on the tip of your gun that may harden and dry up. Remove any excess caulk accumulated on other surfaces using a putty knife. If it’s still wet, use wet fingers to remove it. 

Why Is Window Caulking Necessary For Winter?

Caulking your windows, especially during the winter season, prevents cold air and melting snow from entering your home. It also helps you save on energy bills. Properly caulked windows allow you to enjoy cozy and warm nights. 

The Cold Won’t Bother You If You Calk And Seal

When planning to caulk your windows, it’s important to follow the proper steps to ensure you won’t have any air leaks and prevent wasting caulking material. The right steps will also help you create a more smoothened and professional look for your windows.

Editorial Contributors
Matt Greenfield

Matt Greenfield

Matt Greenfield is an experienced writer specializing in home improvement topics. He has a passion for educating and empowering homeowners to make informed decisions about their properties. Matt's writing focuses on a range of topics, including windows, flooring, HVAC, and construction materials. With a background in construction and home renovation, Matt is well-versed in the latest trends and techniques in the industry. His articles offer practical advice and expert insights that help readers tackle their home improvement projects with confidence. Whether you're a DIY enthusiast or a seasoned professional, Matt's writing is sure to provide valuable guidance and inspiration.

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