10 Best Exterior Caulks 2025 in the United States

The OSI Quad Max Window, Door and Siding Sealant is a high-performing exterior caulk that offers several impressive features. It stands out for its strong adhesion to various materials and exceptional resistance to environmental factors like UV rays, dirt, dust, and extreme temperatures. This makes it a reliable choice for outdoor applications where the sealant is exposed to harsh conditions. Additionally, its ability to be applied on wet surfaces offers greater flexibility during installation.

The product's 5x stretch and Class 50 Joint Movement capability ensure long-term durability without shrinkage or bubbling, making it suitable for areas prone to movement or stress. One of its notable strengths is the fast cure time – it's paintable within just one hour and fully cures in 24 hours, allowing for quicker project completion and effective protection against air and moisture infiltration. This feature is particularly beneficial for contractors and homeowners looking to expedite their projects.

Another advantage is the availability of training and support from OSI, which includes best practice guides and installation training programs, ensuring users can achieve optimal results. On the downside, the sealant comes only in a clear color, which might not be ideal for all aesthetic preferences. Additionally, while the product is marketed as a professional choice, it might be overkill for simple, DIY home repairs where a less robust option could suffice. The sealant is packaged in a 9.5 fl oz cartridge, making it necessary to have a caulking gun for application, which could be a limitation for some users. However, for those needing a durable and flexible sealant capable of withstanding extreme conditions, the OSI Quad Max is a strong contender.

The Gorilla Waterproof Caulk & Seal 100% Silicone Sealant is a versatile and durable option for anyone needing to seal out water, air, and moisture. Its standout feature is its quick curing time; it becomes water-ready in just 30 minutes, which is an excellent advantage for those needing a fast solution.

Additionally, its mold and mildew resistance ensures long-lasting performance without yellowing, shrinking, or cracking, making it suitable for both indoor and outdoor use in various weather conditions. The flexibility and strong adhesion of this sealant allow it to be used on a wide range of surfaces, including stainless steel, wood, glass, and more.

However, it should be noted that being 100% silicone, this sealant may not be paintable, which can be a limitation if you want to match the color of the sealed area with the surrounding environment. The 10-ounce cartridge size is standard but might not be enough for larger projects. This product is excellent for quick repairs and versatile applications, especially where durability and resistance to elements are critical.

The Gorilla Waterproof Caulk & Seal 100% Silicone Sealant is a versatile option for various sealing needs. It excels in weather resistance, making it suitable for both indoor and outdoor use. This caulk is great for kitchens, bathrooms, windows, doors, and even more challenging environments like auto and marine applications.

One of its standout features is the quick cure time; it can be exposed to water in just 30 minutes under the right conditions, although it's generally safer to wait 24 hours for it to cure fully. The mold and mildew resistance ensures longevity without yellowing, shrinking, or cracking, which is ideal for maintaining a clean and durable seal over time.

Additionally, it adheres well to a wide range of materials, including stainless steel, porcelain, wood, and glass, among others, enhancing its flexibility and usability in different scenarios. However, since it is 100% silicone, it means you cannot paint over it, which might be a drawback if you need the sealant to match a particular color. The 2.8oz squeeze tube size makes it convenient for smaller projects, but it might not be sufficient for larger jobs. Gorilla's sealant is best suited for those looking for a strong, durable seal that resists harsh conditions and doesn't require painting.