RV caulk, or sealant, may be something you don’t think about very much. But it plays an important role in the life of every RVer. Caulk is an essential part of RV living.

Leaks are the bane of an RVer’s existence, but the good news is that leaks can be stopped and more importantly, prevented!

Today we’ve got some RV caulk talk for you, so let’s get rolling!

Types of RV Caulk and Sealant

The first thing an RVer needs to know about caulks and sealants is that there are considerable differences between one type and another. When you head down the caulk and sealant aisle of a hardware store, you’ll find a wide array of options. Choosing the right RV caulk for your particular situation is essential. Let’s take a look at the options so that you can determine which is best for your application.

Self-Leveling Sealant

The best RV caulk for horizontal surfaces is a self-leveling sealant.
Self-leveling sealant is best for use with horizontal applications such as around a vent pipe on the roof.

When applying this type of caulk, it stays soft long enough to allow gravity to level it into a nice smooth surface. As a result, it’s only for use on horizontal surfaces, like your roof, as it will run or sag on vertical surfaces. It’s a polyurethane composite, and when used, it expands (self-levels) into the joints and cracks to seal them. Once dry, it creates a seal resistant to deterioration from water, stress, and movement, since it stays pliable.

Non-Self-Leveling Sealant

Like self-leveling sealant, this type of RV caulk seals joints and cracks to resist water and stress. The main difference is that you need to manually spread non-self-leveling sealant; it doesn’t self-level or spread on its own. This type of bond is best for sealing vertical areas, as it won’t run.

Butyl Tape

Butyl tape (sometimes called “putty tape”) is a versatile sealant in tape form. It’s pliable and comes on a roll, like other types of tape, making it easy to apply. It can be used on most surfaces, and it doesn’t make a mess like other sealants can. It’s one of the easiest ways to seal between items, such as when installing a window awning, or replacing a roof vent. It comes in a peel-and-stick roll that you can use as needed with minimal cleanup. It can be used on its own, to seal between two surfaces… but we often use it in conjunction with another sealant, like Dicor Self-Leveling applied around the edges.

Dicor BT-1834-1 1/8" x 3/4" x 30' Butyl Seal Tape
  • Dicor Butyl Tape - Ideal for sealing uniquely shaped joints
  • Installs quickly, without gaps

Eternabond

Eternabond tape seals very strongly.
Eternabond tape uses resins and rubber to form a seal that is extremely reliable and durable.

Eternabond also comes in a peel-and-stick roll. Made from a combination of resins and rubbers with a primer added, this sealant works wonders to seal important areas like rooftops. Its bond may not be truly “eternal”… but it’s close! So don’t use Eternabond for anything temporary!

How to Know What Type of RV Caulk to Use for Different Jobs

When considering the type of RV caulk you need for a particular application, the elasticity of the products is an important factor. That’s because RVs move and flex as they travel down the road. More rigid caulks are more prone to cracking or shaking loose during vibration. While “caulk” and “sealant” generally refer to the same family of products, sealants tend to be more flexible, making them great for use on RVs.

Maintaining the RV caulk around rooftop items is essential to keeping your RV leak-free.
Regular maintenance of the self-leveling sealant around rooftop items like your fan keeps these areas leak-free for the life of the RV.

You’ll use each bonding product for specific fixes. Self-leveling sealants are handy when it comes time to repair a roof or horizontal surface. Non-self-leveling sealants are best for vertical surfaces, giving you control over where to place the sealant for maximum effect.

Eternabond tape is a bit pricier, but it can be easier and more efficient to use. It comes in rolls similar to any heavy-duty tape (in different widths) and is strong and flexible. It’s virtually mess-free and works exceptionally well. Many people have solved their leak issues with a simple application of Eternabond.

Keep in mind that adhesive tapes like Eternabond are more difficult to remove. So, if you know you may need to replace the application later, consider using a sealant instead. An example would be sealing around vents or doors.

Additionally, since tapes are more expensive than sealants, a large area in need of repair can get expensive quickly. Most RV owners find that tapes are much easier and faster to apply, so consider your cost versus your time when choosing the best product for you.

Popular Brands of RV Caulk and Sealant

While brand names aren’t everything when choosing the right product, sometimes it’s nice to stick with a reputable brand. Some of our favorite caulk and sealant brands include the following:

Dicor

Dicor offers a variety of self-leveling and non-self-leveling sealants. You can use both quite effectively when you need RV sealant repairs.

You can use Dicor’s self-leveling and non-leveling sealants to create secondary seals around roof edges or vents. They work well with most types of materials such as aluminum, fiberglass, and more. They won’t stain or discolor on application, nor will they fade or deteriorate due to sun and weather. They also come in six different shades to match your color needs.

You’ll find many quality RV caulking and sealants at Dicor, including butyl foam core rolls, other adhesives, and roof coating systems.

Dicor 501LSW-1 Epdm Self-Leveling Lap Sealant-10.3 Oz. Tube, White, 10.3 Fluid_Ounces (Packaging May Vary)
  • Creates a secure, secondary seal along the roof’s edges, air vents, vent pipes and screw heads
  • Adheres firmly to aluminum, mortar, wood, vinyl, galvanized metal, fiberglass and concrete

Eternabond

Eternabond is one of the only RV caulking types of sealant that’s made in a tape form and will stop almost any leak or prevent one. A wide variety of people use and love Eternabond. It’s trusted for its ease of use and quality.

Eternabond provides a virtually permanent bond to almost any surface and works well for most non-pressurized leaks. RVers frequently use it on their roofs to prevent leaks because it’s easy to use with minimal mess. It also comes in several colors (white, black, and gray) and different widths (from 2 to 10 inches) so you can choose the right one for the job.

Sale
EternaBond H.B. Fuller RoofSeal White 4" x50' MicroSealant UV Stable Seam Repair Tape | 35 mil Total Thickness | EB-RW040-50R - One-Step Durable, Waterproof and Airtight Repair
  • MULTI-USE: Perferct for use on metal buildings, trailer/RV roofs and sides, drain pans, drain pipes, boats, canoes. bonds to a wide range of surfaces...
  • NO ADDITIONAL SEALING REQUIRED: Aluminum backing, combined with a layer of advanced MicroSealant, creates a waterproof, moisture, and air tight...
Sale
EternaBond EB-RB040-50R Roof Seal, Black, 4 Inch X 50 Feet
  • Perfect for reseaming all roofs, regardless of the material
  • Proven to be UV stable

SikaFlex

Sikaflex polyurethane sealants are some of the best for heavy-duty projects. Their products stay where they are and resist dirt and grime. You can paint the dried sealant any color and immerse it in water.

While SikaFlex products are mostly for sealing concrete expansion joints, they work well for other sealant needs. And they won’t leave you wondering if you did the job right. The quality speaks for itself.

Sale
Sikaflex-221, White, multi-purpose sealant/adhesive, polyurethane fast curing sealant, 10.1 fl. oz Cartridge
  • Highly elastic and multi-purpose, Sikaflex-221 is suitable for making permanent elastic seals of high adhesive strength.
  • PERFORMANCE: 1-C formulation. NSF approved for drinkable water and incidental food contact. Can be sanded and painted.

GeoCel

GeoCel is a leader when it comes to roofing sealants. But they also specialize in other sealants and adhesives for RV caulking needs and building repair jobs.

Their Pro Flex line of sealants will last and withstand almost anything you can throw at them. Pro Flex will seal any leaks, cracks, and crevices you have. It comes in either clear or white, so you can choose the one that works best for your application.

Sale
Geocel 28100V Pro Flex Crystal Clear RV Flexible Sealant - 10 oz, Quantity 1 (GC28100)
  • Flash Point: 93.0 Degrees_Celsius
  • Excellent Adhesion To Many Surfaces, Even When Damp

Why You Shouldn’t Use Plain Silicone to Seal Your RV

RVs move, shift, and vibrate, and silicone dries down to a fairly stiff consistency that isn’t pliable enough for most RV applications. It’s generally strong enough to avoid cracking, but movement and vibration can cause it to separate from the RV’s surface.

Since the silicone itself isn’t likely to crack, that surface separation can go undetected until a leak occurs. Because of this, silicone sealant generally isn’t the right choice for most RV applications. Just about the only place we use silicone sealant in our RV is indoors in the shower, just like in a sticks & bricks house.

One other problem with silicone is that virtually nothing will stick to it. Not paint. Not any other type of sealant or adhesive.  Even if you remove silicone, the remaining residue will prevent adhesion from any other material. That means once you use silicone, you’re stuck with it… or a very involved clean-up job trying to remove every bit of silicone residue so anything else will stick.

The Right RV Caulk Will Keep Your Rig Dry

RV caulks/sealants need to be able to withstand movement. They’re generally flexible, so they contract and expand as needed. Many of them are removable and can withstand the effects of UV rays. Do yourself a favor when repairing your RV with caulking: Choose the right tool for the job.

Whether you’re sealing a roof, installing equipment that requires penetrating the roof or a wall, or dealing with a fairly major leak in your RV, knowing what type of RV caulk to use is key. Understanding this information is half the battle.

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11 comments
  1. Thanks for the post on sealants. We have a Newmar Class A with every body seam sealed at the factory with some type of clear caulk. They even caulk the rubber window gaskets. Which of the products you mentioned can be used to reapply the seal on the Newmar body? I’m aware that your coach is also Newmar and so hoping you have already researched this with them. I can’t find any information about the caulk they use at the factory in the literature that came with our Class A.

    1. Hi Raymond. That’s a good question. Believe it or not… those seals all around the body work on our ’05 are still in great shape. We haven’t had to touch them since we bought this RV new. But, now that you mention it, we’re not sure what that material is. Ours is clear, as well… and does, indeed, look like silicone. We’d be surprised if that’s what they used… but we’d suggest that your best bet would be to call Newmar and ask them directly. Give them your Newmar coach serial number (if you don’t, we found ours printed on a label inside one of our cabinets in the kitchen, although it could be in your bathroom, too… ours is a 6-digit number) and they should be able to tell you what they used there as a sealant, so you can be sure to replace/repair it with the same thing.

  2. Good video, thanks for the summary and short descriptions of the most important roof accessory any RV owner will use every year.

    When you say “We’ve just been overwhelmed with work. . .” it made me think about your business. If you were to post a list of your RV Park clients I would make sure to use them if they were on or near our route when travelling. Just as they support you we’d be please to support them.

    Along that line: yesterday I talked to Neil Johnson in Kamloops when booking some service. When I said I’m calling Cummins Kamloops for my coach service HE asked ME if it was because of the RVgeeks discount! I said ‘Yes’ and said we can not make it there before the discount is due to expire at the end of July but still “would like to come to them after what John & Peter said”.

    With the COVID travel restrictions/recommendations still in place in BC Neil said he’d call his superiors to see if they can extend the RVgeek deal and let me have it when I come in.

    If you don’t want your RV Park client list public then I will understand. (Perhaps a patreon only perk?)

    Take care,

    John

    1. Great to hear about Cummins Kamloops, John. They’re awesome.

      Thanks so much for the thought about our customers. But when we get hired to build a website for an RV park, that doesn’t include an evaluation on our part about the quality of the park. Over the years we’ve surely done sites for parks we wouldn’t personally want to stay at, so just because we work for them doesn’t mean we necessarily recommend them! LOL

  3. Have to disagree with you a bit on Silicon sealants. While I know they are not self-sealing in the same way that Dicor is, I have found that for most applications they work incredibly well, and even better than others -as long as they are properly applied (which is really true for ALL sealants).

    By that I mean – the surfaces to be sealed must be clean and dry (true for using all types), but where the use of these sealants typically goes wrong is that they are not usually pressed into the cracks and crevices of what is being sealed. I seen a number of instructions for them (as well as for other types) where they simply have you squeeze out a bead of sealant – and that’s it! I have found that virtually all non-self leveling sealants really need to be forced down into cracks of sealing areas using a finger tip or specialized sealant tool which compresses and forms it into a neat, professional bead. Once that is done they self-adhere really well and seal tightly.

    The other things I like about Silicon Sealants are:
    (1) They are available everywhere – Ace, Home Depot, Lowes
    (2) They are available in a number of different colors – usually Black, White and Clear, but have also seen Grey, Tan and Brown.
    (3) Much less expensive than all the other sealants you mention above (usually 1/2 – 1/3 of the price of the ones mentioned above).
    (4) They also work very well as adhesives, making strong, waterproof seals. You did mention that they tend to cure somewhat firmer than others – which is true – but that also makes them work well for bonding purposes too. Used in this way they not only bond tightly, but at the same time provide a good waterproof seal.
    (5) They are still plenty flexible enough to withstand vibration, and they are UV resistant.

    Bu thanks for the article – hope we meet up on the road someday!

    1. Hi Raymond! We’re still making YouTube videos… we’ve published 5 new videos already this year, and have more on tap. We’ve just been overwhelmed with work the past several months (we design websites for RV Parks) as well as a few other projects, so haven’t had time to edit videos. But stay tuned!

  4. FWIW, I have used Flex Seal Flex Shot with success to repair areas of missing caulk along the roof line. I have also used Flex Seal spray over the sealant of roof penetrations where the original sealant appears to be drying out. I clean fist with isopropyl alcohol. Flex Seal products are rubber based, stick to any clean surface and do not crack. Flex Seal products are not cheap but if they work, who cares?

      1. Same experience for me as well. My personal experience with flex seal is that it is more asphalt based than rubber and cracks easily.

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We're handy RVers, not professional technicians. We're happy with the techniques and products we use, but be sure to confirm that all methods and materials you use are compatible with your equipment and abilities. Regardless of what we recommend, consult a professional if you're unsure about working on your RV. Any task you perform or product you purchase based on any information we provide is strictly at your own risk.

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