Best RV Caulk: Prevent Your Roof From Leaking

Stop leaks before they start with an easy-to-apply and durable RV caulk product.

byHeather Fishel| UPDATED Jun 9, 2022 6:48 AM

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Best RV Caulk: Prevent Your Roof From Leaking

Summary List 

Best Quick-Drying: Sika Sikaflex-221 Sealant

Why Trust Us

Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.

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Our Methodology

I chose the best RV caulk options by taking a look at the most highly recommended and best-loved caulks online. I sought out products that RV owners turn to regularly, including those from reputable brands with easy-to-use, long-lasting reputations. The caulks that made the list were those that can meet a variety of sealant or caulking needs, and they all offer durability, a strong weather-ready seal, and the ability to prevent leaks under all kinds of outdoor conditions. I also included options for different needs and price points. 

Best RV Caulk Reviews & Recommendations

Specs

  • Size: 10.3 ounces
  • Caulk Type: Self-leveling
  • Use On: Horizontal RV surfaces

Pros

  • Works on rubber, metal, fiberglass, aluminum, wood, and TPO
  • UV-stabilized
  • Remains flexible once applied
  • Long-lasting and durable

Cons

  • Can irritate nose, eyes, and skin when applying

When it comes to capable RV caulk, a tube of Dicor Self-Leveling Lap Sealant really delivers. This impressive sealant is self-leveling, which saves you time and effort during the application process and provides a nice even seal wherever it’s applied. Meant for use on horizontal surfaces like the roof, it’s strong enough to seal a variety of materials, including fiberglass, rubber, TPO, aluminum and other metals, and wood. You can put it along your roof edges, around vent edges and vent pipes, over screw heads, and around air conditioners, for a few ideas. The caulk is UV-stabilized to prevent deterioration and fading over time, and it remains flexible once cured to handle temperature extremes.

The only potential downside to this caulk? It’s a strong formula, so it can be pretty potent to work with; it can cause nose, throat, eye, and skin irritation. To avoid this, make sure you’re applying the caulk in a well-ventilated area (or outdoors).

Specs

  • Size: 10.3 ounces
  • Caulk Type: Self-leveling
  • Use On: Horizontal RV surfaces

Pros

  • Low-VOC formula
  • Affordable
  • Blocks air and moisture
  • Withstands weather exposure and conditions

Cons

  • Only works on fiberglass, metal, and rubber

Affordable in price and able to cover plenty of distance with just a bead-sized bit applied, Alpha Systems Self-Leveling Lap Sealant gives you a great bang for your buck. A 1/4-inch dab will seal up areas of about 30 linear feet, allowing a little tube to go quite a long way. Plus, this caulk is both versatile and durable. Apply it to rubber, metal, or fiberglass on your RV, and it’ll block out air and moisture, sealing up leaks and preventing them before they become serious problems. Once cured, it’ll stand up to all kinds of outdoor wear and tear, including weather changes and shifting temperatures. It’s also designed to hold up against shock, vibrations, and stress while your camper is in motion.

Just keep in mind that since this RV caulk is self-leveling, it’s only suitable for horizontal applications. Additionally, it can’t be used to create a seal on all materials; it’s only recommended for rubber, metal, and fiberglass.

Specs

  • Size: 10 ounces
  • Caulk Type: Non-self leveling
  • Use On: All surfaces except traffic-bearing surfaces

Pros

  • Adheres to a variety of materials and surfaces
  • Works and seals even on damp, oily, or frozen surfaces
  • Resists dirt adhesion
  • Can be resealed over time

Cons

  • Gloves should be worn during application
  • Hard to smooth out when excess is applied

The Geocel Pro Flex Crystal Clear RV Sealant is a great option if you’re seeking some versatility from your camper’s caulk. You don’t have to worry about blending the color into your RV’s exterior; it’s clear when applied and when dry, and it can be painted over if you’d like. This caulk is also nicely versatile. It can be used on materials like glass, aluminum and other metals, coated steel, wood, fiberglass, and even vinyl. Once bonded and cured, the caulk stays flexible and will expand or contract as joint movement or temperature changes happen. It’s also able to withstand weather exposure (including rough weather conditions). And smoothing this caulk can be as easy as using your finger.

However, before you stick your bare finger into this caulk, make sure to wear gloves. Users note that it’s incredibly sticky and, once dry, pretty hard to get off your skin. It’s even hard to get off fabric, should you try using any to wipe up excess caulk. And it can be tricky to level perfectly if you’ve applied a bit too much.

Specs

  • Size: 10.1 ounces
  • Caulk Type: Self-leveling
  • Use On: Horizontal RV surfaces

Pros

  • Easy-flowing silicone formula
  • Adheres to most materials and surfaces
  • Permanently flexible once cured
  • Professional-level results

Cons

  • Caulk can get sticky as it ages

Make sealing and caulking a breeze and choose Heng’s NuFlex 311 Self-Leveling RV Sealant. This silicone-based solution will stop leaks, strengthen cracks, and add a tough, leakproof seal across your camper’s horizontal surfaces. While it’s best used for roof applications, this self-leveling caulk doesn’t require any fuss, smoothing, or pressure. It flows smoothly, making application easy; once cured, it’s smooth and professional-looking in its finish. Plus, after this caulk is used to seal joints, roof vents, AC units, and more, it provides strong, durable adhesion. Yet it also remains flexible enough to adjust and adapt to temperature changes, movements, and other common challenges.

The only downside is that as this caulk ages, it can dry out and become tough to work with. If you’re thinking about buying multiple tubes to keep for years, you may only want to keep what you’re going to use within months or a year.

Best Quick-Drying
Sika Sikaflex-221 Sealant

Specs

  • Size: 10.1 ounces
  • Caulk Type: Non-self leveling
  • Use On: Any RV surface

Pros

  • Strong, permanent adhesion
  • Weather-resistant
  • Works on a variety of surfaces and materials
  • Sandable and paintable

Cons

  • Comes out slowly and can be stiff

There’s no need to wait for hours or even a full day after applying RV caulk when you’re working with Sika Sikaflex-221 Sealant. This tough caulk will add a seriously strong and permanent seal wherever it’s applied, and it’ll be ready to hit the road after just three hours of dry time. This capable caulk features a polyurethane formula that cures fast, and it can be used on RVs, trailers, and even vans. The secret to its quick curing? The caulk cures in atmospheric humidity and creates a durable elastomer substance. It’s elastic and non-corrosive, which means it stays flexible without causing any damage. You’ll also find this sealing caulk to be weather-resistant, safe for incidental food contact, and approved for areas near potable water.

The only real downside to this non-self leveling caulk is it’s stiff and hard to apply. You’ll definitely need some force to get the slow-moving, thick solution out of the tube, but it’ll definitely stay wherever it’s applied once you do so.

Specs

  • Size: 4 in W x 25 ft L
  • Caulk Type: Putty tape
  • Use On: All RV roofs

Pros

  • Works on EPDM, TPO, metal, fiberglass, and more
  • Effortless application with no wait
  • Won’t harden, crack, or shrink
  • Works on aged surfaces

Cons

  • Can ruin scissors with adhesive

If you’re in need of a super convenient, quick solution to make repairs to your RV’s rook, Quick Roof Extreme Repair Tape will get the job done. This roll of putty tape is super adhesive, with a highly tacky sticky side and a bright white surface color. Wherever it’s applied, it instantly adheres and stops leaks, giving you a permanent repair in just seconds. And it works across a wide variety of roof materials, including EPDM, TPO, metal, fiberglass, vinyl, wood, and more. Plus, this caulk tape is backed by a guarantee: It won’t harden, crack, or shrink after it’s been applied. You can put this tape to work on vents, skylights, awnings, and more when you need caulk ASAP.

When you’re working with this tape, however, be cautious with the scissors. It’s so tacky that the adhesive can actually stick to your scissor’s blades, wrecking their ability to cut.

Our Verdict

A must-have for every RV owner and a highly durable, reliable product, Dicor Self-Leveling Lap Sealant is a caulk that can easily and quickly seal up any areas that might be prone to leaks or cracks. If you’re looking for a more affordable product with good value, Alpha Systems Self-Leveling Lap Sealant is another great option that delivers strength and durability for the long term. 

Things to Consider Before Buying RV Caulk

Not all RV caulk is the same, so when you’re shopping for a solid solution for seams, cracks, and other areas that might spring a leak in inclement weather, here’s what you should look for.

Types of RV Caulk

Self-Leveling

When you’re dealing with liquid (well, semi-liquid but thick) RV caulk and want to make sure it applies evenly and smoothly across a surface, self-leveling is a great choice. This kind of caulk stays soft and malleable long enough that it can automatically level itself out for a flat, strongly-sealed final result. It’s a great choice for any horizontal surface, like an RV roof or around horizontally laying vent seams. And once it dries, you’ll get a seal strong enough to resist water, stress, and movement. However, because it remains soft for longer, it isn’t a good option for vertical surfaces; if used vertically, it can drip, run, or sag.

Non-Self Leveling

The alternative to a self-leveling RV caulk is a non-self leveling caulk formula. These sealants are just as strong as the self-leveling variety, though they don’t expand or contract once applied because they stay more solidly in place. A non-self leveling caulk must be manually spread, and you’ll need to carefully smooth and level it out yourself while you’re applying. It won’t run, which can be a little easier to manage, but it’s really best for vertical surfaces and controlled applications. Once dry, this kind of RV caulk will resist water and stress, preventing cracks from forming and spreading. 

Butyl (or “Putty”) Tape

If you don’t want to mess around with traditional caulk, there is an easier and more convenient solution: butyl tape. Also known as putty tape, this solid, low-maintenance form of caulk is actually a roll of tape that’s pliable and easy to apply just about anywhere, on surfaces of all kinds. It doesn’t make a mess, there’s no leveling required, and you can apply it in seconds. But while this tough tape is super convenient, it’s also pretty expensive. It’s really best for small repairs or seals, as it can cost an awful lot to cover large areas with putty tape. Additionally, while butyl tape can be used alone, it’s really most effective with another sealant added around its edges, which can curl up or wear over time. 

RV Caulk Pricing 

RV caulk is, generally, pretty affordable. Sold in small tubes that can cover individual seams, leaks, cracks, and more, your typical container of caulk will cost between $8 and $15. However, if you’re opting for caulk in the form of tape (butyl or putty tape), you should expect to spend anywhere from $20 to $35 for a roll or two. You’ll also encounter higher prices if you buy caulk tubes in bulk packages of three or more, but these can provide great value if you always want to have caulk on hand. 

FAQs 

You’ve got questions. The Drive has answers.

Q: Can I use silicone caulk on my RV roof?

A: Yes! Silicone caulk works perfectly on roof cracks, around the edges of windows, skylights, and vents, or anywhere else your roof might need a little TLC. 

Q: Should you clean an RV before caulking? 

A: You definitely want to perform a little surface prep before applying caulk to any of your RV’s surfaces. Whether you’re working on a large or small area, you’ll want to do a quick cleaning and wipe away any residues, dirt, or debris that may be hanging around. This ensures you’ll get a true, effective seal from your sealant.

Q: What can you use to seal RV seams?

A: You can use liquid caulk or tape caulk to seal up your RV seams. It’s entirely up to your preference – tape is super convenient, but it’s expensive, while liquid caulk can be a bit messy.

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