The 10 Best RV Caulks – [2021 reviews]

Fixing gaps and holes can be a tiresome job for RV owners. But it is also one of the most important aspects of maintaining a motorhome.

To effectively seal any holes and keep your RV in prime condition, a good RV caulk becomes essential.

Settling for an average RV caulk is not the best plan as you can seriously damage the vehicle. Use a reliable product like the 3M Marine Adhesive Sealant. It offers the best UV resistance on the market and adheres to a wide range of materials with ease.

For a detailed review of the 3M Marine Adhesive Sealant and many other sealing options, continue reading this article about the best rv caulk.

Best RV Caulk: Product Previews

 

Detailed Product Descriptions

1. #1 The Best RV Caulk: 3M Marine Adhesive Sealant 4000 UV

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Impressive Features:

• The Best RV Caulk on the market.
• Flexible and durable elastomeric bonding.
• Highly UV resistant.
• Long-lasting polymer.
• Completely watertight after application.

Are you located in or traveling to a sunny state?

Try the 3M Marine Adhesive Sealant. It is by far the most UV-resistant RV caulk we have come across. It offers a medium strength bond with amazing waterproofing capabilities.

It cures to form a tough, rubbery waterproof seal. After completely curing, it remains flexible for quite some time. For areas that tend to shrink, swell, and vibrate this is the best choice. It will remain firmly attached for years to come.

You can use the 3M Sealant for attaching, bonding, and sealing the interiors of your RV. Suitable for use on aluminum, Gelcoat, wood, and fiberglass, this RV caulk performs admirably under harsh conditions. It provides a durable seal that can withstand the elements.

For a great look, you can paint over it immediately after application. This is a feature not seen in many sealants, and lets you put any worries about messing up the RV’s appearance to rest.

We went through hundreds of products, but this one provided extreme UV resistance and extraordinary water sealing. Very few other RV caulks provided these features to the same extent.

As mentioned, the sealant is firm and rubbery, making it ideal for most RVers. You can use it to seal the exterior or interior of your vehicle very easily. Its phenomenal composition allows it to stand up to vibrations.

We found two drawbacks, though. First, it’s a trick to apply, especially for beginners. The other thing is it’s a bit pricier than other options.

With time and practice, however, you can get great results. If you can expand your budget, this is a great investment for RV owners.

2. Geocel Pro Flex RV Flexible Sealant

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Impressive Features:

• Transparent formula.
• Adheres to any damp, frozen, or oily surface.
• Water-resistant.

RV owners know the importance of preventing water from seeping into the small cracks of their vehicles. This can lead to serious troubles down the road; therefore, a high-quality caulk becomes mandatory. This is where the Geocel Pro Flex RV Flexible Sealant comes in.

The Geocel Pro Flex RV sealant tightly seals any holes or leaks on your RV. It is exceptionally simple to use and resistant to cracking. Thanks to its transparency, this multi-purpose sealant designed for RVs won’t stand out. However if you still want to paint over it, you easily can.

The sealant creates watertight seals on your RV seams, trim, and roof. It can also cover tricky spots near the vents, windows, and doors. Its adherence to fiberglass, glass, steel, coated steel, wood, and vinyl makes it one of the most versatile options on the list.

One vital factor is that this RV caulk is not suitable for skylight glazing surfaces. Other than that, this is a great product.

As Geocel claims this is a flexible sealant, we put it to the test. It withstands cold or hot climates and withstands movement without cracking.

This flexible sealant is also UV resistant making it ideal for sunnier conditions. It is resistant to dirt and quite easy to maintain. Once cured, you won’t need to deal with mildew or mold either.

The Geocel Pro Flex RV Sealant features a non-stringing formulation that is easy to apply. Even for beginners, its flexibility makes the application process less stressful. If you make a mistake, you can easily clean it up.

This product boasts a 25-year life expectancy, which is commendable. If you’re looking for a versatile sealant that is good value for money, this one by Geocel is just what you need.

3. Dicor Self-Leveling Lap Sealant

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Impressive Features:

• Reinforced to fight against the sun’s UV rays.
• Effective on a wide range of surfaces.
• Waterproof formula.

This self-leveling lap sealant does a commendable job at closing gaps on your RV roof and seams. Since it is self-leveling, we don’t recommend using it on vertical seams. That will only create an unnecessary mess. As for horizontal seams, it levels evenly and flattens on its own to fill leak spots and holes providing a smooth finish.

What we loved about this product is it works with all types of roofs. It is UV-stabilized and treated to prevent the color from fading under the harsh sunlight. The Dicor Self-Leveling Lap Sealant is available in multiple colors.

You can get an individual tube or get a great deal on 25 tubes of sealant. The latter may seem over-the-top but as an RVer, you’ll need to go through many of these tubes. So, if you want to stock up for the future, we’d say it is a good idea.

A major drawback, however, is it leaves behind a mess. Yes, the application process is a breeze, but it leaves behind a sticky residue that you need to clean up quickly.

This product is available in multiple shades including white, adding to its usability. Since it is UV stabilized, you don’t have to worry about any discoloration either.

This flexible sealant is easy to apply and quick setting. Just four hours after application, the Dicor Self-Leveling Lap Sealant forms a waterproof seal. So, if you apply it to a dry surface, it won’t need a lot of time to set in place.

Overall, this is a reliable and self-leveling RV caulk that can help you seal holes in a jiffy. You can get a single tube or stock up with the 25-tube pack to ensure you have one of these handy whenever you want.

4. Sashco Clear Lexel Adhesive Caulk

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Impressive Features:

• Available in transparent color.
• Ideal for sealing internal and external holes and gaps in RVs and campers.
• Adheres to most surfaces.
• Waterproof and anti-freezing formula.

You can use the Sashco Clear Lexel Adhesive Caulk on your RV’s interior and exterior. Its transparent formula does not mess with your RV’s appearance. Still, if you’d like to paint over it, this adhesive sealant is easy to paint, too.

It seals gaps around your shower, side vents, or on the roof of your RV. The Lexel Adhesive Caulk adheres to most surfaces including metals, plastics, and wood. However, this product does not adhere well to rubber or polystyrene foams. Before you buy it, we recommend checking its compatibility with the material you want to use it on.

Even if you don’t have any gap or hole that needs urgent fixing, the Sascho Clear Lexel Adhesive Caulk is great to simply have around.

This sealant offers maximum flexibility by handling up to 400% joint movement. If you own a camper, you know how valuable this feature is.

With the Sascho Clear Lexel Adhesive Caulk, you can say goodbye to yellowing. Even after regular UV exposure, the clear finish will remain intact.

If you use it to cover crevices inside the RV, it also withstands abrasive cleaners and scouring pads. Nothing beats this phenomenal RV caulk if you ask us.

Another advantage is it sticks to wet surfaces, too!

You can use the sealant immediately, even if it has just rained outside. It is waterproof and does not freeze during application. The Sascho Clear Lexel Adhesive Caulk is the perfect solution for your sealant needs. Wherever you are, this clear sealant works amazingly to stop water damage even before it starts.

All things considered, if an effective, multi-purpose, and easy to use sealant is what you want, we highly recommend this one by Sascho.

 

5. ToughGrade Self-Leveling RV Lap Sealant

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Impressive Features:

• Available in a four-pack.
• Designed to seal horizontal rubber surfaces.
• UV stabilized to prevent cracking and discoloration.

This sealant is just what you need to seal horizontal surfaces on your RV. It is specifically designed for use on rubber roofs but is compatible with most materials.

This popular sealant bonds aluminum, galvanized metal, vinyl, wood, and concrete. Therefore, it is one of the most versatile bonding agents on the market. Besides sealing your RV’s EPDM roof, this amazing product is also capable of sealing vent covers, pipes, screw heads, and your air conditioning units.

As the name indicates, it does feature a self-leveling formula ensuring an easy and thorough application.

This sealant does a great job protecting your vehicle in different conditions by providing enhanced weather protection. Not only that, but it is also UV stabilized. No matter how long you leave it in the sun, you won’t experience any cracking or discoloration.

Coming to ToughGrade’s self-leveling claim, we weren’t overly impressed. The sealant itself is extremely straightforward to apply – you can use any standard caulk gun for it – but it does not self-level as much as the other options we came across. So, be prepared to level this sealant with a putty knife.

If you’re looking for a cheaper solution to reseal your vehicle’s roof, the ToughGrade Self-Leveling RV Lap Sealant is a good pick. It is affordable and comes in a four-pack. This saves you a lot as compared to buying individual units. With that said, it represents good value for money and can easily cover the roof of a 30-foot RV.

A minor setback is its creamy yellow color. If you want to use this product without spoiling your trailer’s look, paint over it.

To sum up, the ToughGrade Self-Leveling RV Lap Sealant is a practical RV caulk for sealing rubber roofs.

6. RecPro Self-Leveling RV Sealant

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Impressive Features:

• Capable of withstanding temperatures between -65 degrees and 250 degrees Fahrenheit.
• Self-leveling formula.
• Compatible with TPO or EPDM rubber roofs.
• Resistant to chemicals, grease, salt, oils, and fuel.

Did you like the ToughGrade Self-Leveling RV Lap Sealant, but its questionable self-leveling ability made you look for an alternative?

Try the RecPro Self-Leveling RV Sealant instead. It boasts many similar features but has the upper hand given its effective self-leveling.

For motorhomes with an Alpha Systems roof or a regular EPDM rubber roof, this self-leveling sealant works wonderfully.

Although ideal for flat surfaces, it also comes in handy when fixing leaks around pipes and vents. However, don’t forget the self-leveling nature of this product. You cannot use it on vertical seams of your RV. What we noticed is it dries white. So, you can paint over to get a more harmonized finish that matches your RV’s roof.

This flexible RV caulk resists vibrations and shocks while you’re on the road. Talking about flexibility, the RecPro Self-Leveling RV Sealant can withstand temperatures up to 250 degrees Fahrenheit and as low as -65 degrees. This means this sealant is fully weatherproof. Wherever your next trip is, you can count on it to not crack or deteriorate in any conditions.

The RecPro Self-Leveling RV Sealant is highly resistant to chemicals, grease, salt, oils, and fuel. So, if it comes in contact with any of these substances, you won’t see any deterioration. This reliable sealant will continue protecting your RV from water damage.

If you have an EPDM rubber roof, this is a must-have RV caulk for your repair kit. It works wonderfully and is extremely easy to use. Get one now so the next time you need to redo your roof or fill holes near the vent, you can save yourself the trouble of trying a wide variety of products.

7. Dap Clear Silicone Sealant

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Impressive Features:

• Clear, watertight formula.
• Compatible with an array of materials – glass, wood, ceramic, metal, plastic, and rubber.
• Weatherproof and waterproof.

Any seasoned RVer will instantly criticize the inclusion of a silicone sealant in the list. Still, hear us out.

Silicone is often avoided by RVers as an RV sealant. The main reason behind this is it is a nightmare to take off. The next time you need a resealing, you can spend hours removing it. However, if you have the time and patience for it, it is a fairly good sealant.

Its biggest plus point is you won’t have to redo your sealant any time soon. This makes it a low-cost, and effective RV caulk. However, keep in mind you can only use it on the inside of your RV.

The Dap Clear Silicone Sealant is a watertight variant that bonds well with ceramic, glass, metals, wood, and rubbers. You can use it to fix crevices in your shower area, kitchen, and near your windows without any trouble.

This clear silicone sealant is fully weatherproof and waterproof. It can withstand extreme temperatures at both ends of the spectrum without shrinking or cracking.

Once cured, the Dap Clear Silicone Sealant will keep your RV looking its best even in damp conditions. This is because it is mildew resistant. So, you can forget about finding those ugly black spots on your precious vehicle.

It is transparent so you won’t have to paint it to hide it. On the down side, we did go through a tough time with the cartridge.

If you are from the select few RV owners that don’t mind using a silicone RV caulk, this is the product for you. You get great flexibility and exceptional adhesion on a tight budget. If you want a long-lasting sealant for areas that won’t need regular resealing, go for the Dap Clear Silicone Sealant.

8. Sashco Through The Roof Sealant

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Impressive Features:

• Copolymer rubber formulation.
• Compatible with fiberglass, plexiglass, and many other materials.
• Extremely affordable when you opt for a value six-pack.

Looking for a multi-purpose roof sealant?

Your search ends here. The Sascho Through the Roof Sealant is an amazing product formulated using a unique copolymer rubber formula. The result is a transparent seal that lasts for years.

It is suitable for a wide range of materials and surfaces, including fiberglass and plexiglass. With this RV caulk, you get a permanently elastic roof seal. However, remember that it is not compatible with polystyrene insulation.

Besides its extensive compatibility, the Sashco Through the Roof Sealant is fully weatherproof. However, it is not very temperature friendly. It does not freeze but offers a more restrictive range than many other sealants available. It provides coverage in temperatures from 0 to 120 degrees Fahrenheit only.

If you travel in regions with pleasant weather, this sealant can be a great investment.

Although not recommended for extreme temperatures, this sealant still comes in very handy. Using this great product, you can easily fix roofing panels and repair leaks around vents, AC units, and windows in your RV.

You can easily apply it on wet surfaces allowing you to fix leaks on the go. Whenever you spot leakage, use the Sashco Through the Roof Sealant to seal the deal before the leakage worsens and causes any permanent damage to your RV.

For a more budget-friendly option, you can opt for a six-piece value pack instead of buying them individually. This can save you a lot of money, and you’ll get a great product at an unbelievable rate.

So, if you’re looking for a low-cost roof sealant, the Through the Roof by Sashco is an amazing option that provides you with exceptional value for money.

9. Sashco Big Stretch Caulk Cartridge

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Impressive Features:

• Stretches 500% from its original size.
• Includes a no-crack formula.
• Offers water and a weatherproof finish.
• High level of UV and temperature resistance.

We can sum this review up in three words. The Sashco Big Stretch Caulk Cartridge is capable, functional, and long-lasting. Don’t worry, we promised a detailed review, and we aim to deliver.

This small bottle of RV caulk is extremely popular among RV owners for its ability to stretch more than 500% of its original size. So, now you know where it gets its name from.

If like most RVers you’re tired of resealing leakages on your motorhome, this could be the solution. The Sashco Big Stretch Caulk Cartridge uses an elastic, no-crack formula. It is ideal for sealing cracks around windows and doors. It adheres to multiple materials and should therefore work well with any type of RV. Even so, it is always a good idea to double-check its compatibility before buying. Remember, this product is not designed for use on roofs.

The Sashco Big Stretch Caulk offers an immensely high UV resistance. Simply put, you won’t have to worry about replacing the sealant anytime soon. It lasts for a few years and will not crack even under the harshest sunlight.

This sealant is available in multiple colors. Picking a shade that matches your RV or going for the good old invisible finish are the best options you have. For the latter, you could easily paint over it to perfectly match your RV’s appearance.

Unlike other RV caulks, this one boasts a no-odor formula. So, you can seal the RV’s interior or exterior without dealing with any pungent odor.

It is easy to apply and clean in case you make a mistake, which is why it is one of our favorites.

All in all, if you need a premium, ultra-stretchy sealant for your rig, this is another amazing option from Sashco.

10. 2-Pack of Alpha Systems 1021 Self-Leveling RV Sealant

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Impressive Features:

• Works in temperatures as low as -40 degrees Fahrenheit.
• Adheres to most materials including EPDM rubber roofs.
• Features self-leveling abilities.
• Capable of resisting shocks, vibrations, and stress.

The Alpha Systems 1021 Self-Leveling RV Sealant offers exceptional performance. Let’s start with its weather resistance quality. It ensures that snowstorms, sunlight (UV rays), rainstorms, or extreme temperatures do not compromise its adhesion.

It holds up in temperatures as low as -40 degrees Fahrenheit, which is great if you ask us.

It adheres to various materials and surfaces like plastic, metals, and glass. However, it is primarily built for EPDM rubber roofs and Alpha Systems’ own Superflex Roofing. This adds to its versatility. Another contributing factor is its leveling.

The Alpha Systems 1021 is a self-leveling sealant. Its self-leveling abilities aren’t bad either. This significantly reduces the amount of work you need to do applying it.

It is extremely flexible and resists shocks, vibrations, and stress points on its surface. Its only drawback is that as a self-leveling sealant, the Alpha Systems 1021 Sealant is not ideal for vertical surfaces.

If the sealant does not match with your RV’s overall aesthetic, you can easily paint on it to match your vehicle. It won’t peel off or tear when painting on it or your roof. This saves you a lot of time that you’d otherwise spend resealing.

The Alpha Systems 1021 Self-Leveling Sealant is available for a reasonable price. You can buy it in a 2-pack or larger quantities to save you even more money. This speaks volumes about the company’s dedication to serving its customers in the best way possible.

Therefore, if you want a roof sealant the Alpha Systems 1021 RV Sealant cuts your work significantly for you. It is a good solution to your caulking problems if you don’t need anything specific.

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Buyers Guide to Buying the Best RV Caulk

To help you find the best sealant for your RV, we have put together a list of considerations that you cannot overlook. If you’ve decided to buy an RV caulk, make sure to answer these questions first.

How Much Can You Spend on an RV Caulk?

An RV Caulk or sealant is something you’ll use more often than you’d initially expected. Don’t compromise on the quality by skimping on the sealant. As you know, cheaper products are generally manufactured using low-quality materials. Always refrain from buying a sealant only because it is cheap.

Remember, quality comes at a price. You cannot buy a $5 sealant and expect it to keep your RV safe from leakage.

However, don’t misunderstand what we mean. A reasonably priced caulk performs admirably, no doubt. Just don’t go for the cheapest sealant you come across.

Is it UV Treated?

When buying an RV caulk, look for a formula with high UV resistance. After some time, sealants that are not UV treated will start cracking and weakening because of the sunlight. This is possible even if you don’t spend a lot of time traveling on sunny days.

A cracked seal may cause damage worth a lot more than investing in a UV resistant RV caulk.

Also, formulas without UV resistance will start fading or yellowing after a few months of exposure. This will diminish the value of your precious vehicle even if the sealant is not leaking.

To avoid caulking for a long time, pick a sealant with great UV resistance.

Is the RV Caulk Waterproof?

RV caulks need to be 100% waterproof. Always make sure that the sealant you pick is water-resistant/waterproof. It is extremely important for your trailer’s safety.

Although sealants generally are waterproof, some options on the market may not be immediately waterproof. You must consider the weather you’re going to travel in. During monsoon, how can you seal a leak while it is heavily raining? Fortunately, some sealants let you achieve this.

If your RV is prone to leakage, we recommend investing in a good waterproof sealant. It provides a great finish even on wet surfaces.

Is It Flexible Enough?

Flexibility is yet another important characteristic when looking for a good RV sealant. Continuously being on the road, excess weather exposure, and constant temperature changes can all damage your RV caulk.

For this reason, we recommend getting a flexible solution. Even when the temperatures go up or down, the sealant continues to work.

RV sealants that lose their flexibility are subject to cracking, peeling, or chipping. Any of these small signs will lead to more permanent damage – a leaking roof, air vent, or window, for example.

As you travel across states with different climates, flexibility becomes extremely important.

Does It Tear Easily?

For areas with a lot of movement, the RV caulk must be extremely tear-resistant. A truly flexible RV caulk, with a good level of tear resistance, helps ensure your seals don’t snap and pull apart easily.

What Are You Sealing and Why?

Surface compatibility is essential when buying an RV caulk. Not all sealants are compatible with the materials you may wish to use them on.

Check the product’s compatibility list before investing in it. Know about the material or surface you will seal using the RV caulk. The next step is to find the product closest to your requirements.

What Are the Different Types of RV Caulk Sealants?

Needless to say, there are many categories of sealants available for your RV. The best ones are typical of six different types.

1. Silicone Caulks

As mentioned previously, silicone caulks are not the go-to option for RV owners. However, if you want a sealant with good anti-mildew properties, nothing beats a silicone caulk.

2. Acrylic Caulks

These are a cheap sealing alternative that provides great value for money. Also, you can easily paint them to match your RV’s shade since they are mostly available in white.

3. Vinyl Caulks

These are quite like the acrylic caulks – reasonably priced and highly paintable. However, vinyl caulks are also prone to cracking if exposed to different weather conditions.

4. Fireproof Caulks

Given that motorhomes are always made using flammable materials, it is not a bad option to get a fireproof caulk. This makes them ideal for joints that move frequently.

5. Synthetic Caulks

Synthetic rubber caulks are extremely flexible and boast amazing adhesive properties. If you want a more forgiving sealant when it comes to varying temperatures, this is it.

6. Modified Silicone Caulks

These are a recent innovation – hybrid caulks that provide the best performance. They are expensive, yet extremely durable. If budget is not a constraint, we recommend going for modified silicone caulk.

What Are the Advantages of Using an RV Caulk?

RV caulks play an important role in every RV owner’s life. They need regular maintenance but also come with their fair share of benefits. Some of them are:

• Preventing leaks
  RV caulks will seal your RV against the elements and any water damage. If you seal any hole with a sealant you can prevent the interior from getting soaked.

• Minimizing Mold or Mildew Formation
  Since their primary goal is to cover gaps to keep your RV dry, RV caulks prevent mold growth too. This can impact our health as microorganisms can find their way into the air you breathe. Use a sealant to prevent your RV from becoming a breeding ground for mold and mildew.

• Keeping Insects and Dirt Out of Your RV
  Insects can enter your vehicle through the smallest of gaps. The same goes for dirt and dust. To avoid this happening, seal the small holes and crevices using a sealant.

• Adding to Your RV’s Value
  Timely replacing of caulk speaks volumes about how well you maintain your RV. If potential buyers look at a well-maintained trailer, complete with fresh caulk, they will pay a higher price for it.

The Bottom Line

Before you hit the road with your RV, make sure to fill in the gaps and crevices with a good sealant. If not, water may easily find its way into your RV and cause more damage than you bargained for. Don’t save a few dollars only to pay thousands of dollars later on.

Before buying an RV caulk, make sure you consider all the factors discussed in this post. If you’re still confused about picking the best sealant for your RV, pick any of the ten best RV caulks on our list. They are all great and thoroughly tested by our experts.