What Is The Best Caulking For Windows?

The type of caulking you choose plays a huge role in determining its effectiveness in sealing different windows. Each product has different properties, strengths, and weaknesses, which make it suitable for specific applications and conditions.

At McClellands Contracting and Roofing, we have worked with all kinds of window caulking products over the years. Today, we will explore the best caulking for windows, analyzed and selected by our experts. 

Choose the right caulk and ensure your windows are sturdy and sealed!

5 Best Types Of Caulks For Windows

We’ve assessed each caulk for durability, weatherproofing, paintability, and compatibility with different window materials. Here are the top-performing window caulks:

#1 Silicone Caulk

Silicone caulks are highly versatile and widely regarded as one of the best caulks for sealing windows. They offer excellent adhesion to various materials, including wood, metal, vinyl, and fiberglass. Silicone caulks are highly flexible, durable, and weather-resistant, making them suitable for outdoor applications. They maintain their flexibility over time, ensuring a long-lasting seal that can withstand temperature fluctuations, UV exposure, and moisture. Silicone caulks are also waterproof and provide superior protection against water infiltration, preventing leaks and moisture-related damage. Additionally, silicone caulks are paintable and environmentally friendly, with a low VOC (volatile organic compounds) content.

Best Silicone Caulking Product For Windows: Gorilla Waterproof Caulk & Seal 100% Silicone Sealant

This silicone caulk stands out for its exceptional performance both indoors and outdoors, making it a top recommendation from many experts. The Gorilla Silicone Sealant effectively seals gaps and cracks around windows, and has impressive qualities such as mold and mildew resistance, quick drying time, and a clear finish when dry. Its versatility allows it to adhere to most surfaces, and its resilience against water exposure, even within 30 minutes of application.

#2 Polyurethane Caulk

Polyurethane is another top-performing window caulking material, particularly in high-stress areas or where movement is expected. They offer superior adhesion and flexibility, allowing them to accommodate building movement without cracking or pulling away. Polyurethane caulks are durable and weather-resistant, providing long-lasting protection against air and water infiltration. This type of window caulking product is suitable for both indoor and outdoor use and can adhere to a wide range of window frames and siding materials, including wood, metal, concrete, and masonry. However, polyurethane caulks may require longer curing times and proper ventilation due to their higher VOC content.

Best Window Caulking Product With Polyurethane Formulation: OSI® QUAD®  Window, Door & Siding Sealant

The OSI QUAD Window, Door & Siding Sealant has multiple professional-grade features. Its thick seal offers unparalleled strength and resilience against dirt and UV exposure, ensuring long-lasting protection for windows. While it may require a bit more investment and skill to apply compared to other options, the OSI QUAD Sealant is unmatched in durability and effectiveness.

#3 Acrylic Latex Caulk

Acrylic latex caulks are popular for general purpose sealing around windows, offering good adhesion and flexibility at affordable rates. They are easy to apply, clean up with water, and dry quickly, making them ideal for DIY projects. Acrylic latex caulks are suitable for indoor use and may be used for exterior applications in areas with minimal exposure to moisture and weathering. While not as durable or weather-resistant as silicone or polyurethane caulks, acrylic latex caulks provide adequate sealing for windows in moderate conditions and can be painted to match the surrounding surfaces.

Best Window Caulking Product With Acrylic Latex Formulation: GREAT STUFF™ Premium Painters Latex Clear Siliconized Acrylic Caulk

This acrylic latex caulk is fortified with silicone emulsion, offering exceptional versatility and performance for window sealing projects. The Premium Painters Latex Clear Siliconized Acrylic Caulk adheres to all porous surfaces, ensuring a perfect fit for your window frames. This caulk is best for sealing cracks, seams, and connection joints with up to 7.5% movement in various window and siding materials.

#4 Hybrid Caulk

Hybrid caulking products combine the best qualities of silicone and polyurethane caulks, offering excellent adhesion, flexibility, durability, and weather-resistance. They are suitable for sealing most construction components, including windows, and provide long-lasting protection against air and water infiltration. Hybrid caulks are best for windows in terms of being paintable and environmentally friendly. They offer versatility and performance comparable to silicone and polyurethane caulks, making them a preferred choice for demanding sealing tasks.

Best Window Caulking Product With Hybrid Formulation: AMP Advanced Modified Polymer All Weather Window, Door and Siding Sealant by DAP

The AMP All Weather Sealant is an excellent hybrid caulk for windows. Its ability to be applied on damp surfaces reduces prep time and allows for immediate application, regardless of weather conditions. Additionally, its fast drying time and UV resistance ensure durability and protection against the elements, while its compatibility with a wide range of materials and paintability provide a seamless finish.

#5 Butyl Rubber Caulk

Butyl rubber caulk is known for its exceptional adhesion and weather-resistance, making this material ideal for exterior windows. Butyl rubber caulk forms a durable and flexible seal that can withstand temperature fluctuations, UV exposure, and harsh weather conditions. Butyl rubber is one of the best caulking materials for windows due to its excellent water resistance and other features. Butyl rubber caulks are highly resistant to shrinking and cracking, maintaining their integrity over time. While not as commonly used as silicone or polyurethane caulks, this kind of sealant is a reliable choice for homes in regions with high exposure to moisture and extreme weather.

Best Window Caulking Product With Butyl Formulation: 12SK Hi-Flex Butyl Sealant

With its flexibility, durability, and weather-resistance, ASI 12SK Sealant is perfect for sealing right angles and window and door joints. This window caulk is UV resistant and provides a reliable seal that can withstand fierce weather. This paintable butyl sealant is suitable for sealing joints up to 1-inch wide, making it a versatile and effective solution for window caulking.

Before purchasing any product, you should find out if caulking is even the right solution for your windows. Caulk serves several important purposes for windows, but it also has limitations. Here's what caulking can and cannot do for windows:

What Caulk Does For Windows

Caulk is primarily used to seal gaps and cracks around windows, preventing air and water infiltration. Here are the benefits of caulking your windows properly:

Improves Energy Efficiency

By sealing air leaks, caulking helps improve the energy efficiency of windows. This can lead to lower heating and cooling costs by reducing the loss of conditioned air and preventing drafts.

Prevents Water Damage

Caulking creates a waterproof seal around windows, preventing water from seeping into the building. This helps prevent water damage to the window frames, surrounding walls, and interior surfaces.

Enhances Comfort

Caulking helps maintain a more consistent indoor temperature by reducing drafts and preventing cold air infiltration in the winter and hot air infiltration in the summer. This can enhance comfort levels inside the home.

Increases Lifespan

Properly sealed windows are less susceptible to moisture-related issues such as rot, decay, and mold growth. Caulking helps protect window frames and surrounding structures, increasing their lifespan.

What Caulk Does Not Do For Windows

Caulking will not be the right solution if you have these issues with your windows:

Repair Structural Damage

Caulking cannot repair significant structural damage to windows or window frames. It only seals existing gaps and cracks to prevent further damage.

Fix Operational Issues

Caulking cannot fix operational issues with windows, such as broken hardware, malfunctioning mechanisms, or damaged seals between window panes. These issues require proper repairs or replacements.

Provide Structural Support

Caulking does not provide structural support or reinforcement for windows. It is solely a sealing material designed to fill gaps and cracks.

Last Indefinitely

While caulk can provide long-lasting protection, it is not permanent and may degrade over time due to exposure to weather, UV radiation, and normal wear and tear. Periodic inspection and maintenance are necessary to ensure the caulk remains effective.

Substitute For Proper Installation

Caulking should not be used as a substitute for proper window installation. It is intended to supplement the installation process by sealing gaps and joints, but it cannot compensate for poor installation practices or structural deficiencies.

We hope this information helps you select the right caulking product and window repair solution for your home. If you have any questions, feel free to connect with our experts over a free consultation.

We Are Pittsburgh’s Most Trusted Window Contractors!

At McClellands Contracting and Roofing, we have the best window experts on our team who excel in recaulking, repairing, and installing windows. Numerous homeowners trust our friendly and professional window specialists in Pittsburgh! If you need caulking or any other repairs for your windows, call us at (412) 353-5660 for professional advice and excellent window services.