The once-simple act of buying a tube of caulk has become a frustrating challenge for DIYers and professional contractors. Walk into any home center or hardware store, and you’ll find a dizzying array of caulks, sealants, adhesives, cements, and mastics — all designed to seal gaps, fill cracks, plug holes, and bond to various building materials.
The result of all these options is that it’s often difficult to find the most appropriate caulk for your specific project. However, within the sea of caulking tubes lining the store shelves is a family of superior products known as elastomeric sealants.
About Elastomeric Sealants
Elastomeric sealants have a well-earned reputation for being extremely durable, tenaciously strong, and easy to apply. Once fully cured, they’re resilient yet flexible to accommodate any expansion and contraction, a phenomenon known as dynamic joint movement.
These sealants can be used indoors or out and will bond to virtually any building material, including wood, steel, stone, tile, brick, glass, plastics, and vinyl.
Most importantly, elastomeric sealants are highly resistant to seasonal movement and long-term exposure to the elements, which are the top two reasons why most caulks fail.
They’re especially effective when bridging a gap between two dissimilar materials, such as vinyl siding and wood trim, which tend to expand and contract at different rates based on temperature and humidity.
When you’re sealing a joint that must stay sealed, you need an elastomeric sealant.
Elastomeric sealants cure to a rubbery consistency, allowing them to flex rather than crack or fail when the materials they are bonding move. This flexibility makes them ideal for indoor and outdoor use and in areas that endure expansion and contraction.
Common applications for elastomeric sealants include:
- Sealing gaps and joints in siding, windows, doors, trim, and roofing
- Filling cracks in concrete driveways, sidewalks, foundations, and masonry
- Waterproofing gutters, flashing, pipes, vents, and ductwork
- Adhering surface materials like tile, wood, metal, and glass
Compared to other caulks and adhesives, elastomeric sealants have superior flexibility, strength, and weather resistance. However, it’s important to choose the right formula for your specific application.
Choosing the Right Sealant for the Job
Several types of elastomerics, including those that are polymer- and acrylic-based, are formulated to meet the needs of specific tasks.
Here’s a brief look at the six most popular types:
Siding elastomeric, such as Titebond All-Siding Sealant, is an exterior-grade sealant that bonds to all types of house siding, including wood, vinyl, aluminum, brick, and fiber-cement — even if the surfaces are damp.
Apply it in low temperatures, and, like other elastomerics, it offers excellent flexibility to withstand expansion and contraction because of the weather.
Titebond’s All-Siding is also highly mildew-resistant, paintable, cleans up with water, and forms an impenetrable barrier against air infiltration, insects, and radon gas. I’ve used it to adhere loose siding and to seal around doors, windows, soffits, and awnings.
Siding elastomeric sealants are formulated to flex rather than crack or fail as siding expands and contracts with temperature changes. Using the right siding sealant helps prevent air and water infiltration that can lead to rot, mold growth, and high energy bills. Titebond’s All-Siding sealant is designed specifically for sealing gaps and joints in all types of exterior siding.
Window-and-Door Elastomeric Sealant
To stop cold drafts from blowing into your home, use a window-and-door elastomeric sealant, which will provide a weather-proof seal against wind and rain. Apply a continuous bead of sealant around the window and door frames and between any house trim and siding. This specially formulated elastomeric will bond to all types of siding and trim boards, including wood, composites, and cellular PVC.
Be sure you can apply the window-and-door elastomeric sealant you buy in low temperatures, it has zero shrinkage, and is either paintable or available in a wide range of colors. For example, Titebond WeatherMaster Sealant comes in over 200 colors.
Window and door elastomeric sealants flex rather than crack or fail as the materials expand and contract.
Proper sealing prevents air and water infiltration that can lead to rot, mold growth, and high energy bills. Use Titebond’s WeatherMaster for windows and doors that go through extreme expansion and contraction.
Rain Gutter Sealant
Rain gutters and downspouts typically have several joints and seams that can leak. Fortunately, elastomerics should plug leaks in any aluminum, vinyl, galvanized metal, wood, or copper gutter system.
Titebond WeatherMaster Gutter & Seam Sealant is a long-lasting, extreme-weather polymer elastomeric that you can apply in temperatures as low as 0° F, and, once cured, can withstand temperatures ranging from -75° to 300° F. And unlike many other caulks, Titebond WeatherMaster Gutter & Seam Sealant will adhere to Kynar, which is a fluoropolymer resin coating applied to many types of metal gutters.
Gutter elastomeric sealants resist weathering, allowing them to maintain a watertight seal on gutter seams and joints despite expansion, contraction, rain, snow, and temperature extremes. Titebond’s Gutter & Seam Sealant bonds reliably to common gutter materials, including Kynar-coated metal.
When working with metal, especially metal roofing, you need a long-lasting, reliable elastomeric sealant that you can trust to fill joints and seams and seal out the weather.
I recommend Titebond WeatherMaster Metal Roof Sealant, a polymer-based elastomeric that offers uncompromising performance and adhesion to all coated and uncoated metals, including aluminum, galvanized steel, copper, sheet metal, and Kynar-coated metal. You can apply it in temperatures as low as 0° F, and it won’t crack or shrink. Besides use on metal roofing, this sealant also seals gutters, roof vents, flashing, siding, and areas around windows and doors.
Metal roof elastomeric sealants resist weathering, allowing them to maintain a watertight seal on metal roof seams and joints despite expansion, contraction, rain, snow, and temperature extremes. Titebond’s Metal Roof Sealant tolerates the extreme expansion and contraction metal roofing undergoes, offering reliable adhesion and flexibility.
For all other jobs, use a multi-purpose elastomeric, such as Titebond DuraMaster Sealant. You can use this sealant for a wide variety of caulking tasks, both inside and out. It forms a durable bond to virtually any clean surface and can span gaps up to 2 inches wide. Plus, it’s crack-proof, mold and mildew-resistant, paintable, cleans up with water, and comes in 13 colors.
Multi-purpose elastomeric sealants offer the same durability, flexibility, and adhesion as specialized formulas while working on a wider variety of materials and applications. Titebond’s DuraMaster bonds reliably to common building materials, including wood, metal, masonry, glass, and vinyl. Its flexibility allows it to seal gaps and joints exposed to expansion and contraction.
When evaluating elastomeric sealants, check that the product offers long-term flexibility, shrink and crack resistance, strong adhesion to the materials you want to caulk, and durability when exposed to weather, sun, and moisture over time. Carefully follow the manufacturer’s instructions for surface prep and application. Proper sealant selection and application technique will determine how well the sealant performs.
So, Is Elastomeric Sealant the Best Caulk for Your Project?
Elastomeric sealants offer unrivaled durability, flexibility, and longevity compared to latex and silicone caulks. Their ability to resist cracking and weathering over time makes them ideal for sealing gaps and joints exposed to expansion, contraction, or outdoor elements.
However, elastomeric sealants have some drawbacks. They tend to be more expensive than other caulk types. Most formulations also have strong fumes during application and cure time. Proper ventilation is a must.
For indoor tasks like sealing trim, elastomeric sealants may be overkill. Here, flexible paintable latex caulks often perform just fine at a lower cost.
So, weigh the pros and cons relative to your specific project. Elastomeric sealants are the top choice for sealing windows, doors, siding, roofing, and gutters. But for everyday interior gaps and cracks, a simpler latex or silicone caulk may meet your needs.
FAQs About Elastomeric Sealants
What are some common applications for elastomeric sealants?
Elastomeric sealants excel at sealing exterior gaps and joints exposed to weather and expansion/contraction, such as those around windows, doors, siding, roofing, gutters, flashing, and vents. They also work well for filling cracks and gaps in concrete and masonry.
How do elastomeric sealants compare to latex or silicone caulk?
Elastomeric sealants are far more flexible, durable, and weather/UV resistant than latex or silicone. However, they tend to be more expensive. Latex works fine for basic interior gaps. Silicone offers decent exterior sealant performance at a moderate cost.
What prep work is required before applying an elastomeric sealant?
Proper surface cleaning and preparation are vital for good adhesion. Remove any old caulk, dirt, dust, or oil from the crack or seam. Porous surfaces may require a primer. Apply sealant within 30 minutes of the primer drying.
Can elastomeric sealants be painted over?
Most elastomeric sealants accept paint once fully cured. Check manufacturer guidelines for cure time and paintability. Some may require a specialty bonding primer for best paint adhesion.
How long does an elastomeric sealant last?
When properly applied, elastomeric sealants typically last 10 to 20 years or more before needing replacement. Their flexibility, strength, and UV resistance give them exceptional durability compared to other caulk types.