To properly seal a window frame, you will need to choose the right sealant before doing anything else.

Next, you have to remove the old sealant, clean the surface before applying the sealant primer, then apply the sealant and shape the joints to your liking.

Learn how to seal windows frames by reading this article. 

    Why Is Sealing Window Frames Important?

    Because these openings enable air to move into and out of the structure, heating and cooling costs are increased. Condensation caused by this airflow can also lead to premature deterioration of the building’s structure and windows.

    Sealing windows can also increase energy efficiency. Heat and cold are kept inside throughout the winter and summer months when windows and doors are properly sealed. Drafts can be caused by poor sealing, which makes it much harder for air conditioning units to manage the temperature.


    Where To Check When Reapplying Window Frame Sealant?

    Doing a visual check can determine if a window needs to be resealed or just repaired. Examine the regions where the frame of the windows meets the wall and the intersections of different portions of windows. 

    A draught emanating from your window region, or traces of condensation on inside panels of the glass panes, are other indicators.

    Read Also: How to repair window seal

    7 Steps To Properly Seal Window Frames Outside

    What You’ll Need

    • Putty knife or scraper
    • Long nail or wire hanger
    • Caulk
    • Caulk gun
    • Small plastic spoon or ice cream stick

    Steps To Follow

    1. Select The Right Sealant

    Depending on the project’s requirements, you will need to choose the proper caulk and dispenser. However, there are things you need to think about. Consider the need to paint over the caulk, its resistance to water and moisture, and whether you’ll be applying it indoors or outdoors.

    2. Remove Any Existing Sealant

    Remove old caulk before applying new caulk. You can use a retractable razor blade scraper to prepare the surfaces to remove the existing caulk.

    Depending on the age of the caulk job and the positioning of the caulk bead, a putty knife or scraper may also be useful. Use a cloth and rubbing alcohol to wipe the surfaces. Porcelain or ceramic surfaces must be completely smooth, clean, and dry to receive fresh caulk.

    3. Prepare The Surface

    Mask off both surfaces using blue painter’s tape to the edge of the caulk bead to stop. Make sure the tape is straight and that you use big amounts of tape rather than short bits. 

    The joint will appear best if you tape in a pretty thin line, around 1/4 inch wide. The caulk bead may need to be broader, up to 3/8 inch, for uneven joints.

    Firmly press down on the inside edges of the tape. The idea is to seal these borders so that caulk does not leak underneath, which can be done using a wooden craft stick or your fingernail.

    4. Apply Backer Rods For Wider Gaps

    If you have wider gaps between the frame itself and the wall, you can use backer rods to support you during the application process.

    5. Apply Your Sealant/ Caulk

    Cut the tip of the nozzle at a 45-degree angle with a utility knife to open the caulk tube. Use a long nail or wire into the nozzle to puncture its seal. To guarantee a smooth flow of caulk, you can poke a few times through the seal.

    Caulk should be applied at a 45-degree angle between horizontal and perpendicular. Squeeze hard into the frame to get the caulk into the joint.

    Draw the caulk tube tip along the length of the joint while carefully squeezing the caulk gun handle, working at a steady and constant pace. The better the ultimate results, the smoother the initial application.

    6. Shave Off Any Excess Beads

    Wet a small plastic spoon, ice cream stick, or your finger with rubbing alcohol (for silicone caulk) or water, depending on the type of caulk you used (for latex caulk). 

    Also, moisten a corner of a cotton rag with water or alcohol, if needed. The alcohol or water will act as a lubricant and thinning agent as you smooth the joint. Smooth the caulk joint with gentle pressure, working your way from one end to the other. 

    7. Reinstall Dismantled Trims If Any

    If you have disassembled or dismantled any trims or other additional parts, you can reassemble and install them back, and you’re done.

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    Types of Sealant/ Caulk That You Should Be Aware Of

    Many people are surprised to discover so many different varieties of caulk available. It’s crucial to choose a product that suits your needs. 

    1. Acrylic Latex Caulk

    Acrylic latex caulk is water-based, meaning there are no harmful chemical components, and it is simple to clean up.

    Additionally, it can be painted or pre-tinted to match existing color schemes, although it is not especially weather- or temperature-resistant. It’s best suited for use in the home.

    2. Butyl Rubber Caulk

    Butyl rubber caulk is commonly used to seal gutters, flashings, roof repairs, and similar areas.

    3. Latex Caulk With Silicone

    Latex caulk with silicone has improved water resistance and is recommended for indoor and outdoor applications.

    4. Masonry Repair Caulk

    Sealing seams in masonry, stucco, and concrete slabs with very flexible caulk. Some are latex-based, while others are solvent-based and require mineral spirits to clean up.

    5. Polyurethane Caulks

    Polyurethane caulks are based on a solvent. Thus, they are extremely effective. Working with them might be a little more difficult than working with silicone caulks. 

    Most common housing materials can be bonded with polyurethane caulks. However, when exposed to UV light, they can degrade over time.

    6. Pure Silicone Caulk

    Pure silicone caulk is appropriate for high-moisture areas such as tubs and showers, and it is a little more pricey. It does not accept paint, although it comes in various colors to suit your preferences.


    To avoid drafts, conserve energy, and protect moisture from destroying the wooden window pieces, caulk the frames. Water can penetrate between the window and the siding if it isn’t properly sealed, causing it to quickly decay.

    Editorial Contributors
    avatar for 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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