Exterior caulk is a thick, viscous solution that comes in a long tube and is applied with a caulking gun. It is designed to seal seams in windows, doors, siding, gutters, brick, concrete, and roofing tiles to ensure that your home remains waterproof. Exterior caulks are easy to use and are a great, inexpensive option to fix a variety of cracks and breaks around the exterior of your home.
The best exterior caulk for your home depends on the areas you will be sealing, the material you want to bind together, the size of the crack or gap you need to fill, and whether the caulk needs to be paintable or in a pre-made color. Most importantly, the product you choose needs to be high quality if it’s going to protect your home. Take a look at the top products below to get an idea of what the best exterior caulk for you might look like.
Types of Exterior Caulk
Several different types of exterior caulk are available, including latex, acrylic, silicone, polyurethane, and butyl rubber exterior caulk. Each type has its own pros and cons, so it’s good to familiarize with the available options to see which is best for your project.
Using a latex base for your exterior caulk is a good option for cities or states with relatively consistent temperatures throughout the year since once an exterior latex caulk has cured, it no longer expands or contracts with the material around it. While latex caulk can be painted, the paint may crack and flake during extreme temperature changes. This type of exterior caulk is also typically the least expensive and must be replaced more often than other types of caulk to remain effective.
If you want a longer-lasting product than simple latex caulk but something that is still easy to use, acrylic latex caulk may be a good choice. This formula is also more water resistant than regular latex, providing a better seal against moisture to protect your home from the elements.
This type of exterior caulk is a popular choice for many different materials, including metal, wood, and tile, and comes at a decent price. However, like latex caulk, it will shrink when fully cured and doesn’t expand or contract in response to temperature change. It can be painted, but you may run into the same cracking and peeling problems that can happen with standard latex caulk.
Exterior silicone caulk is the most commonly used type of exterior caulk because of its incredible durability and water resistance. Silicone is also a very flexible material, even after it has cured, making it an ideal option for sealing drafty windows and doors. This type of exterior caulk cannot usually be painted, though many manufacturers offer several different color options.
However, when working with silicone caulk, keep in mind that it doesn’t typically seal well to wood and can be very difficult to remove after it has been applied. Silicone is also more difficult to work with than either latex or acrylic latex caulk, so you will want to take your time and test out the flow of the caulk before applying your first bead.
Polyurethane is one of the best materials to use for sealing the exterior of your home. This exterior caulk is UV resistant, so you won’t have to look at ugly yellowing over time on what was a clear bead of caulking. Exterior polyurethane caulk also has similar flexibility to silicone, allowing it to absorb impact damage or expand and contract with ambient temperatures.
Polyurethane caulk can be painted, allowing you to give your home the flawless aesthetic you desire. And it is great for sealing together different types of materials, such as metal and wood or wood and glass. However, it is very thick and potentially difficult to work with if you don’t have experience with a caulking gun. It’s also one of the more expensive exterior caulk types.
Because of its UV resistance, butyl rubber caulk is primarily used in commercial or industrial settings for sealing exterior locations that are exposed to direct sunlight. This type of exterior caulk is also highly flexible, making it a good option for sealing gutters, chimney flashings, and housing foundations where moisture accumulation and movement are common. Butyl rubber exterior caulk can be applied in both cold and hot temperatures so you won’t have to wait for it to warm up or cool down to waterproof your home. However, to adequately remove stuck-on butyl rubber, you will need to use a solvent, like a paint thinner.
What to Consider When Choosing the Best Exterior Caulk
Before choosing the best exterior caulk to seal up your windows, doors, and siding, there are some factors to consider, such as product durability, how easy it is to use, and how long it will take to cure.
Some areas around your home may go untouched by anyone for years, but they are still exposed to powerful wind, rain, hail, and possibly snow. For this reason, you need to ensure that you are investing in a product with the durability necessary for the application area.
Latex and acrylic latex are the least durable exterior caulks because, once cured, they don’t have the ability to expand and contract. This rigidity causes them to break down much sooner than silicone, polyurethane, or butyl rubber exterior caulk. Silicone has better water resistance than polyurethane but doesn’t adhere well to wood, while polyurethane works with most materials, even forming effective seals between two different materials.
Another important factor to consider when selecting an exterior caulk is how easy it is to use the product. Most caulk products involve placing a tube into a caulking gun and squeezing the trigger until the caulk is pushed out of the tip of the tube. The tip should be directed along the seam you want to seal while squeezing the caulk out of the tube.
However, ease is dependent upon the viscosity and adhesion quality of the exterior caulk. Application is more difficult with dense products like butyl rubber, polyurethane, and silicone because it is harder to control the flow of the caulk through the tip of the tube. Latex and acrylic latex caulk both flow relatively easily from the tube, allowing you to carefully apply them. They are also easier to remove without a lot of mess if you make a mistake.
Most exterior caulks come in a clear or white finish, but some products may offer a selection of color choices so you can match the caulk bead to your exterior design. Color is an important decision to make if you are using a silicone caulk product, as it cannot be painted since paint does not stick to 100 percent silicone caulking.
While you can paint latex and acrylic latex, you may encounter an issue with cracking and peeling paint; these caulks are not flexible enough to expand and contract with the surrounding materials as temperature changes. Polyurethane is a good option if you are set on painting the caulk bead, but in most cases, a clear or white bead of caulk blends in with the exterior design of the house.
The curing time of an exterior caulk product is the length of time it takes for the entire bead of caulk to fully dry from the exterior to the center of the bead. Curing time is a subjective factor and can differ greatly between individual products. To determine how long it will take for the caulk bead to fully cure, you will need to refer to the manufacturer’s directions.
Typically, an exterior caulk product will dry within 30 minutes to 1 hour but can take between 8 hours to 6 days to fully cure depending on the type of caulk, the location, the humidity or moisture in the area, and the amount of caulking used. A very thick bead will take significantly longer to dry through to the center.
Our Top Picks
The products below were chosen for quality and price. Check out this list to discover some of the best exterior caulk on the market for your home.1Photo: amazon.com Check Latest Price
If you need to replace the siding on your home, you will need to apply much more than one 10.1-ounce tube of latex exterior caulk, which is why this value bundle comes with 12 10.1-ounce tubes. The latex caulk comes in white or brown coloring, allowing you to choose a complementary color option for your house. In addition, you can use this caulk to save money on your heating and cooling bills by sealing up draft cracks or holes.
The exterior caulk dries to the touch within about 1 hour, but it isn’t fully cured for up to 24 hours, so prior to that you shouldn’t expose the caulking to excess water. This latex caulk is a great option for siding, trim, molding, baseboards, and wood with mold and mildew resistance to help prevent discoloration, shrinking, and cracking.2Photo: amazon.com Check Latest Price
Concrete repairs can become complex if you are working with a large crack or hole that can only be filled with asphalt or a similar substitute. However, for smaller concrete cracks, you can use the Sashco Slab Concrete Crack Repair Caulk, which is textured to replicate the appearance of concrete once the caulk has cured. The 10.5-ounce tube of exterior caulk is made with a unique formula that can be used to span gaps up to 3 inches.
The gray concrete caulk’s durable design is intended to withstand regular foot and vehicle traffic, so you can apply it to your driveway, patio, and path without worrying that the caulking will be pulled out. This exterior caulk, which takes three to four days to fully cure, is very flexible and should move with the concrete as it shifts, instead of cracking and breaking.3Photo: amazon.com Check Latest Price
Windows and doors require an exterior caulk that can adequately provide a seal against moisture, airflow, and temperature while remaining flexible enough to absorb the kinetic energy from the window or door being open and closed. From GE Sealants & Adhesives, this 10.1-ounce silicone caulk has a clear coloring so you won’t notice it after it has fully cured, which is good, as it’s not paintable.
This exterior caulk formula resists freezing temperatures and is UV resistant so you won’t have to worry about it shrinking or becoming discolored. After application, the silicone caulk is water resistant within 30 minutes, though it takes 24 hours to fully cure. This flexible caulk is formulated to withstand expansion and contraction, making it ideal for windows, door, siding, attics, molding, and vents.4Photo: amazon.com Check Latest Price
Don’t let drafty winds and soaking rain seep through your siding and cause damage to your home. Use Gorilla’s silicone caulk to seal up holes, cracks, or vulnerable seams in your siding. The silicone exterior caulk can be applied along the siding seam and within 30 minutes should be able to provide an effective seal when exposed to water, though the caulk does take 24 hours to fully cure.
This durable silicone caulk remains flexible after curing and won’t yellow, shrink, or crack over time so you won’t have to worry about leaks after it is properly applied. The 10-ounce tube of white exterior caulk should be stored in a cool, dry location when it isn’t in use, and should be applied at temperatures above 40 degrees Fahrenheit to properly cure.5Photo: amazon.com Check Latest Price
Holes in your brick wall can lead to water damage, insect infestations, and cold drafts—and a large enough hole can be an invitation to rats and mice. You can fill those holes with this acrylic latex exterior caulk to properly seal out undesirable pests or weather conditions. The acrylic latex has antimicrobial properties to help protect the caulk against mold and mildew.
You can also use this exterior caulk on painted or unpainted wood, plaster, glass, aluminum, masonry, tile, metal, and concrete. It takes about 1 hour to dry, but about 24 hours to fully cure. With the 10.1-ounce tube, you can choose between white, almond, black, brown, clear, gray, or tan to match your brick or mortar. This caulk also comes in a 5.5-ounce tube, available in white or clear.6Photo: amazon.com Check Latest Price
While a white or clear exterior caulk can blend in with most exterior designs, if you want one consistent color pattern on your home, you may prefer this exterior caulk, which can be painted to your preferred color after it has fully cured. The Gorilla Paintable Silicone Caulk gives you the temperature flexibility of silicone so you can properly seal windows, doors, gutters, trim, and siding.
The 9-ounce tube of silicone caulk takes just 30 minutes after application to be paintable using acrylic latex or latex paint, though it is advised to wait 24 hours to ensure it is fully cured. Once cured, the exterior caulk remains flexible and is mold and mildew resistant as well as waterproof. This white exterior caulk can also be purchased in a value pack of six tubes in case you have a larger project to complete.7Photo: amazon.com Check Latest Price
Holes and cracks in your roof need to be sealed up as soon as possible to prevent moisture from seeping into your home. Designed to seal shingles, gutters, chimneys, skylights, and ducts, this polyurethane exterior caulk is an ideal option for fixing your roof.
The 10.1-ounce tube of exterior caulk’s black color is intended to match or blend with the color of your shingles. However, if you prefer a different look, you can paint this caulk with the color you want, though you may need more than one coat. This exterior caulk takes between four to seven days to fully cure. Once cured, it provides a waterproof seal that remains flexible until it is removed.8Photo: amazon.com Check Latest Price
A leaking gutter system can lead to clogs, broken gutter pieces, and ice buildup in freezing temperatures, but this is a problem that can be easily fixed with Red Devil Silicone Caulk. The 9.8-ounce tube of silicone caulk is compatible with glass, ceramic, and metals, making it a great option for sealing holes and gutter piece connections. The silicone caulk can be removed but will typically require a solvent, like paint thinner, to fully remove the caulk.
You can apply this caulk at freezing temperatures if necessary, so you don’t have to wait to fix leaks until the weather agrees. This silicone caulk takes 24 hours to fully cure and remains flexible after curing, reducing worries about cracking or shrinking.
Tips for Using Exterior Caulk
Adding a line of caulk along your siding or the frame of your window seems like a quick and simple process, but if you don’t remove the old caulk before you begin, the new exterior caulk will never properly seal the gap. The old caulk can be removed with a utility knife and a putty knife, giving you a clean surface to carefully apply the bead.
When you are applying the bead of caulk, ensure that you are gripping the caulking gun with both hands to prevent shaking, slipping, or any other incidental movement that may cause you to lose control and make a mess.
You shouldn’t use caulk for gaps that measure more than ¼-inch in width. This is because the consistency of exterior caulk is not firm enough to retain its form in a large space, causing it to sag out of the gap and create an unnecessary mess. For gaps larger than ¼-inch, you should use a foam backing rod to provide adequate filler and support for the bead of caulking.
FAQs About Exterior Caulk
If you still have questions to help you decide on the best exterior caulk for your needs, keep reading to find answers to some of the most commonly asked questions.
This depends on the type of caulk being used, as some products are specifically designed to be nontoxic. However, most exterior caulk products would contain harmful ingredients if swallowed, and the fumes from the caulk could also pose a danger if you are using it in an enclosed space, like a garage or an enclosed porch.
Yes, you can get exterior caulk that is designed to work on painted and unpainted wood. This caulk also adapts to the swelling and shrinking of wood so the seal remains effective despite the temperature, humidity, and precipitation changes.
To caulk exterior windows, you can follow these simple steps.
To caulk the exterior siding, follow these steps.
Use a utility knife or putty knife to cut through the old caulk, and pull it out with your finger or with pliers. Use the putty knife to scrape off the remaining caulk and sand down the surface, if necessary, to create a clean surface for the new caulk to be applied.