RV Sealant: The Winter Camper’s Best Friend

When winter camping calls, your RV’s ability to stay warm and weatherproof becomes the cornerstone of comfort. Whether you’re navigating snow-covered forests or enjoying a quiet lakeside retreat, the unsung hero of your camper’s winter readiness is its RV sealant.

Making sure your RV is buttoned up effectively protects against cold drafts, moisture, and potential long-term damage. (And sealing up your RV can involved more than just RV sealant.) But to get the results you want, you need to know the basics. So, in this article, we’ll focus specifically on the different types of RV sealant, when and where to use them, and some top product recommendations to make your winter RV adventures cozy and trouble-free. 

 

Why RV Sealants Matter in Winter

As almost all RV owner know (or will soon find out), winter conditions can be brutal on an RV. Ice, snow, and fluctuating temperatures challenge even the most well-maintained rigs. Gaps in seals can allow freezing air or water to creep in, leading to drafty interiors, moisture damage, or even structural issues. This is where RV sealants come to the rescue, acting as a barrier to keep your RV protected and insulated. They help keep the weather out and the comfort inside of your home on wheels.

 

Types of RV Sealants and Their Uses

The world of RV sealants can feel overwhelming, but understanding the key types and their applications will help you choose the right product for each job.

 

1. Self-Leveling Sealants

Best for: Horizontal surfaces like your RV roof. Self-leveling sealants are designed to spread evenly as it cures, creating a smooth, watertight seal on flat areas.

Top Pick: Dicor 501LSW Self-Leveling Lap Sealant

• Why It’s Great: This sealant is a go-to for sealing seams and vents on rubber or TPO roofs. It’s UV-stabilized and resists cracking, which is essential during winter freezes and thaws.
• Pro Tip: Apply on a clear, dry day to allow proper curing before exposing it to snow or rain.

 

2. Non-Sag Sealants

Best for: Vertical surfaces like sidewalls, windows, and doors. Non-sag sealants are formulated to stay in place without dripping or sagging, even on inclined surfaces.

Top Pick: Geocel ProFlex RV Flexible Sealant

• Why It’s Great: Known for its flexibility, ProFlex works well on fiberglass and aluminum and withstands temperature extremes.
• Pro Tip: Use masking tape around your application area for a cleaner finish, especially if working on visible sections like windows.

 

3. Butyl Tape

Best for: Underneath fixtures like vents, skylights, and window frames. Butyl tap is pliable, adhesive tape that conforms to irregular surfaces for an excellent initial seal.

Top Pick: 3M Butyl Tape

• Why It’s Great: Ideal for creating a strong base seal before applying a lap or non-sag sealant over it.
• Pro Tip: Always remove old butyl tape before reapplying to ensure a secure fit.

 

4. Silicone-Based Sealants

Best for: Non-porous surfaces, such as glass or metal. Silicone-based sealants provide excellent water resistance and flexibility, but not suitable for areas exposed to high UV light or on rubber roofs.

Top Pick: Permatex Clear RTV Silicone Adhesive Sealant

• Why It’s Great: This sealant is a reliable option for quick fixes on windows or mirrors.
• Pro Tip: Use sparingly, as silicone can be challenging to remove and is incompatible with some RV surfaces.

 

5. Specialty Sealants for Extreme Conditions

Best for: Areas exposed to heavy wear or harsh weather. These specialty sealants are formulated to handle extreme cold, water immersion, or high movement.

Top Pick: Sikaflex-221 Multi-Purpose Sealant

• Why It’s Great: Known for its durability, it adheres to multiple surfaces, making it versatile for tough jobs.
• Pro Tip: Allow extra curing time in colder temperatures for maximum adhesion.

 

6. Flexible Sealants for All-Weather Versatility

Best for: Sealing joints and cracks that require flexibility and durability. These sealants are weatherproof, paintable, and adaptable to movement. All of which make this kind of RV sealant ideal for RV surfaces prone to shifting or flexing.

Top Pick: Flex Caulk Waterproof and Weatherproof Sealant

• Why It’s Great: Flex Caulk stands out as an all-purpose, heavy-duty sealant perfect for RV use. Its flexible, weatherproof formula makes it an excellent choice for sealing around windows, vents, trim, or any area exposed to movement or environmental stress. The built-in trigger applicator simplifies application, ensuring a precise and clean finish without needing extra tools. Once cured, Flex Caulk dries to a paintable surface, blending seamlessly with your RV’s exterior for a polished, professional look.
• Pro Tip: Plan your application based on weather conditions, as colder or humid environments may slightly extend curing time. For larger projects, keep a damp cloth handy to smooth out edges and achieve an even seal.

 

My Personal Must Haves

With space being a premium in an RV, if I could only have two on the road, it would Dicor Lap Sealant and Flex Caulk. Both are easy to apply and super reliable. We recently used Dicor for our full solar and electrical upgrade when installing new solar panels. Its self-leveling properties and durability made the process seamless and gave us peace of mind for long-term weatherproofing. You can check out the full installation in this video on our Instagram. 

We also use Flex Caulk around the RV in a pinch because it works well and comes with a squeeze handle. So, it is quick and easy to use on the go. There is no caulk gun needed.

 

When and Where to Apply Sealants

Proper application is just as critical as choosing the right sealant. Here’s a breakdown of common areas that benefit from RV sealant maintenance.

Roof Seams and Vents. Check for cracks or peeling sealant, especially around vents, skylights, and air conditioning units. Use self-leveling sealant for the best results.

Windows and Doors. Inspect for gaps where cold air or moisture could seep in. Non-sag sealants or butyl tape work well here.

Underbelly and Storage Compartments. Look for potential openings where road debris or water might infiltrate.

Slide-Out Seals. Ensure the rubber seals are in good condition and supplement with a compatible sealant for gaps.

 

Additional Tips for Winterizing with RV Sealant

Preparation Is Key. Clean all surfaces thoroughly before applying sealant to ensure proper adhesion.

Temperature Matters. Most sealants cure best above 50 degrees Fahrenheit. So, plan applications during milder winter days or indoors.

Inspect Regularly. A quick monthly check of your seals can save you from expensive repairs down the line.

RV sealants may not be the flashiest part of RV maintenance, but they’re undoubtedly among the most important. With the right RV sealant and application, you can ensure your RV stays warm, dry, and comfortable all winter long. Whether you’re boondocking in snowy mountains or parked at your favorite winter campground, a well-sealed RV is the key to worry-free adventures. Don’t overlook this essential step. Your RV (and your wallet) will thank you!