How to Choose the Right Type of Caulk for Your Project
Caulk is a versatile, flexible, multi-purpose sealant. It’s commonly used to fill cracks and gaps around doors, windows, plumbing and pipes, as well as filling in joints, gaps and cracks around windows, doors, and other surfaces. Using caulk helps improve energy efficiency by preventing air leaks. When applied properly, it can also prevent water and bugs from entering your home.
When contemplating your project, knowing the differences between the various types of caulk there are will help you decide what caulk to use for your project. The type of caulk you use depends on the application.
To learn how to use caulk, watch our video: How to Use Caulk.
Caulk vs. Silicone
Although caulk and silicone are both used as sealants, there are differences between the two. Caulk is easy to use, dries quickly and works best for sealing cracks and gaps in areas like baseboards, toilets, trim, moulding, etc. A nice feature of caulk is that it’s paintable, making it more versatile and giving you the option to color match it.
Silicone is waterproof and the more flexible of the two sealants, which is a major plus when dealing with materials that expand and contract. This makes silicone ideal for high-moisture environments, like bathrooms and kitchens. It’s best for larger joints. Silicone can withstand extreme temperatures. Unlike caulk, silicone can’t be painted, but it’s available in array of colors.
Types of Caulk
Latex and silicone caulk are the most common types. The two materials are sometimes combined and sold as siliconized latex or latex plus silicone. These products offer the easy use of latex with the added durability of silicone.
Caulk comes in two forms: a cartridge or a squeeze tube. Using a larger cartridge (usually 9 to 11 ounces) with a caulk gun will result in a continuous bead of caulk. For smaller projects, a smaller squeeze tube (usually 3 to 6 ounces) may be a more convenient choice.
In addition to cartridges and tubes, you can also buy caulk strips. These rolls come with adhesive backing and a fast, no-mess application. With no tools required, these mildew-resistant strips are perfect for sealing bathtubs, showers and wall trim, and can even be applied over existing caulk as a finishing touch.
Acrylic Latex Caulk (also called Latex Caulk)
Known as an all-round good sealant, acrylic latex caulk is sometimes referred to as latex caulk or painters caulk. It’s great for sealing gaps and joints in wood, however, it weakens in extreme temperatures or sunlight.
Benefits of Acrylic Latex Caulk
- Easier to apply and replace
- Can be painted
- Easy to clean with soap and water
- Minimal odor
- Works on porous and nonporous surfaces
- Best suited for constant gaps
Adhesive Caulk
While there are some types of caulks that are intended solely for use as caulk, others work as adhesives also. Adhesive caulk is a little different. It bonds two items or surfaces together. Caulk isn’t intended for this purpose unless it’s specified on the product label. In this case, adhesive caulk is a high strength silicone that’s used to bond.
Benefits of Adhesive Caulk
- Good for filling gaps
- Can be used as an exterior glue
- Flexible
- Prevents cracking as surfaces expand and contract
Polyurethane Sealant
Polyurethane sealant is an organic compound and a waterproof sealant. While it’s mostly used in construction projects, polyurethane sealant can also be used inside. Polyurethane is strong, versatile and flexible and is used to seal gaps and joints.
Benefits of Polyurethane Sealant
- Waterproof sealant
- Works on plastic, metal, wood and more
- Useable in any weather condition
Silicone Caulk
Silicone caulk is a versatile sealant that works indoors and outdoors. It has great adhesion to almost any material (except wood). Because it’s highly flexible and water-resistant, silicone caulk is the best caulk for showers, repairing areas around the sink, bathtub and other areas where moisture is present.
Silicone caulk has a stronger odor than latex, is more difficult to apply or replace and requires mineral spirits for cleanup.
Benefits of Silicone Caulk
- More flexible than latex and holds up to extreme temperatures and sunlight
- Lasts longer
- Works on nonporous surfaces
- Works for gaps that expand, contract or stay constant
Siliconized Acrylic Sealant
Siliconized acrylic sealant is acrylic caulk with silicone added. The addition of silicone makes it a stronger sealant that can stand up better to water.
Benefits of Siliconized Acrylic Sealant
- Easy to work with
- Cleans up easily with water
- Can be painted
- The addition of silicon makes it more flexible and water-resistant
- Great for indoor and outdoor applications
Synthetic Rubber
Synthetic rubber caulk is a strong caulk with excellent adhesion. It’s a good caulk for exteriors and can also be used in interiors.
Benefits of Synthetic Rubber Caulk
- Excellent caulk for exteriors
- Good for cold and wet conditions
- Flexible and expands and contracts as needed
- Paintable
- Can be applied to wet or dry surfaces
- Bonds to practically any surface
Wood Caulk
If you don’t think you need a special caulk for wood, think again. The best product to use when working with wood is wood caulk. Wood caulk is used to fill gaps and cracks in wood. Although you can find special caulking for wood, acrylic latex caulk also works well on wood.
Benefits of Wood Caulk
- Strengthens the wood at the application site
- Some wood caulks are paintable
- Works indoors and outdoors
- Bridges uneven or irregular gaps
Specialty Caulks
For certain projects, you may need a specialty caulk designed for a particular task. You'll always get the best results when you use caulk that's designed for your project's specific conditions. Here are some of the main types of specialty caulks and their key features.
Blacktop and Asphalt Caulk
- Fills cracks in parking lots, driveways and other asphalt surfaces
- Forms a strong waterproof seal
- Resists stains from gas, oil and de-icing salts
Concrete Caulk
- Fills gaps in driveways and sidewalks
- Can be exposed to water shortly after application
- Withstands extreme temperatures
Fire Retardant Caulk
- Seals separations around wires, pipes, HVAC ducts and vents
- Used for chimney/fireplace or other framing gaps
- Made of special material rated for its ability to block fire
- Noncombustible
- Withstands high temperatures
Gutter and Flashing Caulk
- Used around roof vents, gutters, flashing, downspouts and other metal joints
- Withstands extreme temperatures
- Durable and flexible
Mortar Caulk
- Seals leaks and cracks on stucco, mortar, stone, concrete and brick
- Withstands high temperatures
- Blends in with textured surfaces
Molding and Trim Caulk
- Fills gaps between walls and boards
- Crown molding installation
- Quick dry time
- Paintable
Roof Caulk
- Stops minor roof leaks
- Flexible, waterproof and mildew-resistant
Sanded Caulk
- Fills gaps on large joints (1/8 inch or bigger)
- Butt up to and match preexisting tile/sanded grout
- Appears rough and grainy
- Adheres well in wet areas
Unsanded Caulk
- Fills very tight joints
- Joins tile and counters
- Smooth finish
Window and Door Caulk (Interior)
- Window caulking and door maintenance
- Won't shrink or crack
Caulk for Kitchen and Bath
Kitchens and baths are environments in the home where moisture occurs. These areas are more suited to caulk that resists mold and mildew. Silicone sealant creates a water and moisture barrier that protects the area where applied, making it a great sealant for bathtubs. Look for products designated for kitchen and bath applications.
Caulk for Exteriors
A good, high-quality exterior caulk helps protect your home from rot and peeling paint. Silicone-based caulk fills in gaps and cracks and is also great for caulking around doors and windows because they’re prone to moisture and the elements. Antimicrobial properties inhibit mold and mildew growth. Polyurethane caulk is good for trim and other areas that are exposed to the weather.
Benefits of Exterior Caulk
- Used in outdoor trim work
- UV resistant
- Prevents heat loss around windows and doors
- Good for sealing cracks in the foundation of a home
- Protects the exterior from insect and water damage
- Helps with insulation of the home
Caulk Tools and Accessories
While it's important to have the right caulk for the job, having the right tools makes your DIY project easier.
Caulk Singles
These small tubes are good for easy touch-ups around the house such as sealing shower tile or the kitchen sink.
Caulk Cord
It comes in rolls and is used most often for weatherstripping windows and doors. Applied properly, it usually lasts one to two years.
Finishing Tool
Caulk Gun
Coloring
Because latex and some silicone caulk will take paint, you can use white caulk and paint it to match any place you're using it. When using silicone caulk that can't be painted, choose the color that most closely matches the surrounding area, or select clear caulk for an unobtrusive look.
Conclusion
Not all caulks are created equal. Different areas of the home call for different types of caulk. Knowing which type of caulk or sealant works best in a specific area will make your DIY job much easier.
Still not sure which caulk to use? Stop by your local Lowe's and an associate will be happy to help you choose the caulk or sealant that's the best fit for your project.
Frequently Asked Questions About Different Types of Caulk
Choosing the right caulk can sometimes be overwhelming, but we're here to help. Here are a few questions that customers ask the most about the different types of caulk.
How Do I Know What Kind of Caulk to Use?
Determine the application of the caulk — where will you be using it? Acrylic latex caulk is the most common caulk and serves as an all-purpose caulk. For dry areas of the home, areas that don’t see a lot of water and areas where you intend to paint the caulk, select acrylic latex caulk. For applications in areas where moisture or water exists, use a silicone caulk. In the kitchen and bathroom, acrylic and latex caulk are mold- and mildew-resistant.
What is the Best Caulk for Expansion and Contraction?
What Kind of Caulking Hardens?
Concrete caulk dries hard. Additionally, polyurethane sealant cures fast and hard. When used for wood joints, it can then be sanded and painted. Latex caulks also become hard when completely dry.
When Should You Not Use Silicone Caulk?
You shouldn't use silicone caulk on wood as it doesn't adhere well. This includes wood to metal joints because it increases the risk of leaks. Also, if you have a surface that you want painted, don't use silicone caulk because it prevents the paint from bonding.
What's the Difference Between Caulk and Grout?
Caulk
- Caulk comes in a liquid form in a tube.
- After it cures, caulk is still somewhat flexible.
- It's used for sealing cracks and gaps in areas that are exposed to water.
- Caulk is used for many different applications including kitchens, baths, masonry, windows, doors, roofing and more.
Grout
- Grout comes in powder form and needs to be mixed with water.
- It creates a hard surface and isn't flexible.
- It's used between tiles in kitchens and bathrooms to prevent them from moving.
How Long Does it Take Caulk to Dry?
Dry times can vary depending on the type of caulk you're using. Read the manufacturer's directions for your particular product. Here are some general guidelines.
Interior Caulk
- Interior silicone caulk can dry to the touch in as little as 30 minutes.
- Acrylic latex caulk dries to the touch in 30 minutes and fully cures in 24 hours.
- Drywall caulk can dry to the touch in 15 minutes.
Exterior Caulk
- Concrete and masonry caulk cures in 7 days. Humidity can affect drying time.
- Window and door caulk is paintable in an hour and fully cures in 24 hours.
- Roof and flashing caulk dries to the touch in 4 hours.
How to Apply Caulk?
Are you ready to get started? Learn more about how to remove old caulk and apply new caulk.