Best RV Caulks: Seal and Close Gaps Permanently

Prevent leaks and water from entering your RV with these top-rated RV caulks

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BY Linsay Thomas , Scott Roepel / LAST UPDATED ON October 7, 2019

If there are gaps or holes that you need to fill in your RV, you want to use the strongest sealant. Properly closing up any spaces around air conditioners, vents, and windows is a great way to keep the air inside the RV and keep unwanted air out. This can also prevent water damage and block bugs from crawling their way into the camper. Check out these high-quality RV caulks if you need to seal gaps in your motorhome.

Best Overall
M Marine Adhesive Sealant
An extremely strong and durable solution. It’s water-resistant to keep the rain out and strong enough to be used on boats and jet skis.
It’s developed with a tough polyurethane polymer to resist weathering. It can even withstand vibrations and shocks without peeling or cracking.
It can take a while to dry and is not built to be used in extreme heat. While it will last through the heat, installing it in hot temps may make it thin.
Best Overall
M Marine Adhesive Sealant
Best Value
Geocel Pro Flex RV Sealant
The formula is crack resistant yet the solution is flexible and can fit into the smallest spaces with ease. It’s built to last up to 25 years in any weather condition.
The caulk sticks to almost any surface and even works in damp, frozen, and oily conditions. It can withstand movements, bending, and bowing as well.
It may shift colors with time and become more of an off-white shade. It can be a bit messy and is thick out of the bottle
Best Value
Geocel Pro Flex RV Sealant
Honorable Mention
Dicor Non-Sag Roof Lap Sealant
The caulk is reinforced to fight against the sun’s UV rays. This also prevents it from discoloring and deteriorating with time.
It can be used on a variety of materials, including vinyl, aluminum, concrete, and plastic. It creates a watertight seal to protect against rain damage.
It can be a pain to apply and can make a mess because you have to move quickly when applying it. The nozzle can be weak and bend as well.
Honorable Mention
Dicor Non-Sag Roof Lap Sealant

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Benefits of RV Caulk

  • Creates a watertight seal. Caulking around certain joints creates a watertight seal that prevents water from outside from seeping into the cracks and crevices of your RV. If water gets in, it can cause a lot of damage that can be costly to repair. Caulking around fixtures also prevents water from damaging the floor, walls, and cabinets. Caulking can also maintain your RV’s roof, air vents, and venting system.
  • Lower energy costs. Applying caulk can prevent hot or cold air from moving outside. If you don’t caulk the borders around doors, windows, and walls, cool or hot air will escape. As a result, your RV’s heating and cooling usage will increase to make up for the loss, causing energy costs to go up. The drafts will also make it very uncomfortable for you and your family to stay near walls and windows.
  • Protection from outdoor elements. Caulking around trim and windows ensures that no outside elements get inside through the window frame or other gaps. When there is no caulk to prevent blockage, dirt and dust enter the RV more freely. If moisture from rain or snow gets into the RV, it can damage the structure or cause dangerous mold and mildew. Water and mildew stains can appear in the carpet and on the walls.

Types of RV Caulks

Acrylic Latex (Painter’s Caulk)

This is one of the most common acrylic caulks available. It's also one of the most affordable. Like its name suggests, painters use it to cover small cracks and holes and then apply paint on top. This caulk excellently adheres to drywall, wood, mortar, and other absorbent building materials. It dries in approximately one hour and can be painted right away. You can easily clean this caulk with soap and water. Some people also call it "The Painter's Best Friend."

Vinyl Latex

One of the best features of this caulk is it’s designed to be easily applied and cleaned. However, it doesn’t last as long as acrylic latex. The caulk is suitable for use indoors and outdoors, but you have to be careful when using it outdoors. Be sure to choose vinyl latex caulk with a long lifespan, which works best outdoors. However, this caulk is not flexible, so do not use it in areas where contraction and expansion can be a problem.

Pure Silicone

This is the best caulk for sealing your RV shower area for good. It is resistant to mold and mildew, boasts a long lifespan, and works superbly on non-porous surfaces. After application, it can last for decades. However, it does not stick well to porous materials like drywall and wood. Pure silicone caulk is very flexible and strong but can be difficult to clean up. You will need heavy-duty solvents to remove it. It also has a bad smell.

Adhesive Caulk

If you want to attach two materials together for good, use an adhesive caulk. Adhesive caulks stick to just about anything. Some of the caulks are resistant to mold and mildew and are suitable for wet places. Most can be cleaned with water. However, we recommend having a solvent close by because it will come in handy when you're trying to remove caulk from your shoes and clothes.

Top Brands

GE Sealants and Adhesives

This company has a long history of advanced, innovative silicone sealant technology. It was established in the 1950s and is based in Huntersville, North Carolina. Its silicone sealants are completely waterproof and help seal cracks and gaps to prevent water damage. The sealants and adhesives allow you to carry out projects quickly and swiftly. We love the top-rated GE Silicone Door and Window Caulk.

Gorilla Tough

For more than two decades, Gorilla Tough has been selling glue, caulk, sealants, and adhesives. It began as a glue manufacturer and later started producing products like super glue, construction adhesive, tape, and other premium products. The company makes high-quality products that undergo rigorous testing before they are released to the market. Its headquarters are in Cincinnati, Ohio. Be sure to get the Gorilla Silicone Sealant Caulk before you hit the road in your RV.

DAP Products

This company dates back to 1865 when Elmer Wiggim and Robert H. Dicks started making sealing wax for food canning. Canning was a widespread practice in those days before commercially prepared foods and refrigeration were introduced. The company is headquartered in Baltimore, Maryland, and manufacturers silicone sealants, latex caulks, adhesives, patch and repair products, and insulating foams. One of its best bathroom caulks is the DAP Bathroom Silicone Rubber Caulk.

RV Caulk Pricing

  • $5-$10: If you have a small budget, you can get RV caulk in this category. However, most of the caulks here come in small tubes, so it’s important to search carefully.
  • $10-$30: The caulks here are made by popular brands like General Electric, DAP, and Gorilla Tough. They typically come in bigger sizes or in a set.

Key Features

Type of Caulk

The most common reason for caulking is to prevent water penetration which may seriously damage your RV. If you want caulk you can apply on your RVs exterior and trim, choose polyurethane or hybrid caulk. Polyurethane caulks are usually tougher than other caulks and ideal for areas that take a beating. Hybrid caulks merge polyurethane and silicone for top-notch flexibility, adhesion, and durability. They are also easier to apply than polyurethane caulks.


Caulk in bathrooms and kitchens is usually visible, so it's important to choose a product that is easy to apply and looks neat. The caulk also needs to be waterproof and resistant to mold and mildew. Acrylic latex caulks are specially designed for wet areas. They are the easiest to apply and smooth out. They are also the only sealants that can be cleaned with water. Look for a product labeled "plus silicone" or "siliconized" because silicone greatly improves the flexibility and adhesion of caulk. 


Silicone caulk, which also goes by the name rubberized silicone caulk, is a very flexible caulk that remains flexible for most of its lifetime. It does not peel, crack, or distort over the years. It also maintains a waterproof barrier against moisture a lot longer than acrylic caulk. Choose a caulk that is easy to smoothen and offers great elasticity and amazing adhesion. Synthetic rubber is a new type of caulk that's the most flexible yet. It cures clear and can be applied in unfavorable weather conditions.

Other Considerations

  • Color. Latex caulk and some silicone caulk absorb paint. If you don't want the caulk you get to absorb the paint, use white caulk, and paint it to match the surface you’re applying it on. If you’re getting silicone caulk which cannot be painted, pick a color that closely matches the surface. You can also choose a clear caulk for a neat look.
  • Finishing Tool. A finishing tool helps you to create a uniform bead. If you don't have a finishing tool, you can use a wet finger to tool the bead of caulk to create a smooth, clean line and to press the caulk firmly into the joint.

Best RV Caulk Reviews & Recommendations 2021

Best Overall
3M Marine Adhesive Sealant

This marine adhesive sealant cures to form a tough, rubbery waterproof seal. After it is fully cured, it remains flexible for a long period of time. It is suitable for use in areas where swelling, shrinking, vibration, and shock issue. You can apply it on your boat or recreational vehicle and it will remain strong for many years. It is ideal for attaching, bonding, and sealing the interior parts of boats and RVs.

You can also use this permanent adhesive on parts of your boat that are below the waterline and shielded from the sun. 3M has used strong polyurethane polymer to make it, which is why it is resistant to saltwater and weathering. As you move from one place to another in your RV, the sealant stays put and doesn't crack or peel. It maintains a strong bond even when your vehicle vibrates or moves quickly. You can apply this sealant with a manual caulking gun and it will remain workable for up to four hours.

However, you should not apply this caulk when there is extreme heat, as it may thin. It also takes some time to dry.

Best Value
Geocel Pro Flex RV Sealant

If you own a motorhome, you know how serious water damage can be. It's important to prevent water from getting into the smallest parts of your vehicle because this can lead to serious issues later on. A high-quality RV caulk, like the Geocel RV Flexible Sealant, can help prevent the formation of mold and mildew. It offers exceptional flexibility and is resistant to cracking.

The sealant tightly seals any holes or leaks and can connect different types of materials in your RV. It provides excellent adhesion to various surfaces, even damp, frozen, and oily ones. And even when the temperature changes, it will not crack or peel. Its bright white color works well with different surfaces. The sealant's non-stringing formation makes it easy to apply.

However, this sealant has a thick consistency and can create a mess when you’re applying it. And with time, it may change color and become off-white.

Best Non-Staining
Dicor Non-Sag Roof Lap Sealant

Using caulk to seal around your RV's roof edges, air vents, venting system, and air conditioner can help you to avoid spending a lot of money on repairs. Caulking also prevents water from getting into the RV and air from escaping outside. The Dicor Non-Sag Lap Sealant is UV-stabilized and does not lose its color or deteriorate over time. This means it won't stain or discolor the surface where it is applied.

The caulk is ideal for use where self-leveling is not required, like on vertical surfaces. It is compatible with any roofing material and provides excellent adhesion to wood, aluminum, vinyl, galvanized metal, concrete, and mortar. It does not contain any harmful air pollutants and continuously seals and remains flexible for many years.

This RV caulk comes in a white color and can be applied again after the first layer has cured. You can continuously seal the surface and it will remain flexible. 

However, this caulk has a few downsides. You have to work quickly when applying it, as it dries quickly. Because of this, you may end up making a mess. Additionally, its nozzle is not very strong and bends easily.

Premium Pick
Dicor Self-Leveling Lap Sealant

Dicor isn’t new to our list; actually, it’s just one honorable mention before this one, but each product isn’t the same. For those who need to caulk up a small hole or large one, the Dicor Self-Leveling Lap Sealant is a rather capable product. It applies in seconds and does so simply without much fuss. It is a self-leveling caulk, so it will rise and level on its own without any help from you.

One of the best features of the caulk is it is functional with all types of roofs. It’s also UV-stabilized and treated to not deteriorate or discolor after it is applied. As another benefit to you and your RV, the caulk comes as a kit of four at a reasonable price as well. You can stock up and not have to worry about ordering more any time soon.

The one downside that may be an issue to you and the RV is it may leave a mess. Yes, it may be easy to apply the caulk, but doing so may leave behind sticky residue that you will want to clean up quickly. There have also been complaints about the self-leveling aspect of the caulk.

Honorable Mention
Sashco Big Stretch Caulk

This is a small bottle of RV caulk with a big name that is capable, functional, and durable. The Sashco Big Stretch Caulk comes in a 10.5-ounce bottle and is a pure white color that blends in with most RV roofs and panels. It also does exactly what it’s name suggests; it stretches unbelievably well and lasts a long time.

Those who have used the caulk have noted its durability and longevity. After one year on the RV, the caulk still remains as strong and reliable as it did when first applied. There also doesn’t appear to be any shrinkage after the caulk sets and stays on the RV for a few months and up to a year. It’s a handy little container of caulk set at a low price as well.

There have been complaints that the caulk either doesn’t dry or will take a while to fully dry out. You may want to paint it after it sets so dust and dirt don’t stick to it. There have also been mentions of the caulk cracking or splitting after a year or so.

Honorable Mention
AP Products White Sikaflex

AP Products’ RV caulk is developed out of a polyurethane adhesive that increases its effectiveness and functionality. The caulk is available in two colors—white and black—so you are able to cover either the roof color or panels on or in your traveling home. The caulk also comes in an easy-to-use 10.1-ounce canister.

A great feature of the Sikaflex caulk is its ability to withstand shock and road abuse. The material maintains its strength and the adhesive won’t pop off or crack with each bump you hit in the motorhome. It’s even been known to cure and set under colder temperatures so you can apply it without venturing somewhere warmer.

However, it isn’t the cleanest caulk to work with, as it can get all over your skin quite easily. The good news is it wipes clean almost immediately and doesn’t have that sticky gooey feeling. Your fingers may be left dirty, but rubbing alcohol should do the trick. There are also complaints that it does turn yellow after a while

Honorable Mention
ToughGrade Self-Leveling RV Lap Sealant

This is a sealant designed to ensure AC units and window seals are secured and tightly shut so you don’t have a draft on your drive. The caulk seals well and quickly, and effectively prevents any wind, dirt, or dust from entering through any cracks that may be near windows and vents. All you need to apply it is a standard caulking gun and you are good to go.

The best part about ToughGrade’s Self-Leveling RV Lap Sealant is it goes on quickly and takes next to no time at all. It takes around one day to dry out completely and can be applied to just about any roof material. The caulk sheds off water without a problem and can be applied over screws, bolts, and nuts as well.

The one issue you may find with the caulk is it isn’t exactly a pure white color. It is more of a yellowish cream color, so you may want to buy some paint to match your RV. It also doesn’t appear to self-level as well as the Dicor product listed above.

Honorable Mention
RV Flex Repair Self Leveling Caulking Lap Sealant

You can opt for a set of four 10-ounce tubes, or you can go the single tube route as well. The caulk is a white color and can be used on RVs with fiberglass, aluminum, PVC, Kynar, wood, or concrete roofs, making it a versatile and multifunctional caulk for a wide array of motorhomes, tractor trailers, and RVs.

Another great feature of the Flex Repair Self Leveling Caulking Lap Sealant is its ability to be applied in cold or warm temperatures. You won’t have to trouble yourself with driving to a warmer location or parking the RV in a garage, as the caulk can be applied at temperatures as low as 35 degrees Fahrenheit.

However, there have been complaints with the caulk being a bit runny when first opened. You may want to store it somewhere cooler to see if it thickens up at all. Although it does state it can be used between a specific range of temperatures, it doesn’t seem to hold up all that well if it is applied when it is rather hot outside.


  • You should wear gloves when handling caulk. The solution is sticky and can be quite messy.
  • Consider purchasing a tool to spread the caulk before it dries to help make the process easier. These tools are typically a thin sheet of plastic or rubber that repels the substance so it does not stick to it.
  • Once the caulk is dry, you can paint it to match the material it is set against to make the repair less conspicuous. 


Q: How long will it take for RV caulk to dry?

A: This will depend on the brand of caulk you choose. It’s tough to gauge in general, but it can take anywhere from a few minutes to a full day to set up and hold.

Q: Do I have to use the entire bottle of caulk in one sitting?

A: While you do not have to use the whole bottle to seal one gap, you may want to find a reason to use it all. Once open, the compound can freeze up within a few days and make it more difficult to squeeze out. 

Q: How do I use RV caulk?

A: You simply squeeze the tube to get the adhesive out, but that may require a bit of muscle. The easiest way to apply it is by using a caulk gun. It is specifically designed to squeeze out caulk from the tube. By loading the canister into the gun, you can use the trigger to force the compound out much more simply.

Final Thoughts

To properly and permanently seal gaps and holes in your RV, consider the 3M Marine Adhesive Sealant

You can also check out the Geocel Pro Flex RV Sealant to get a tight seal that blocks out rain and keeps the air inside your RV.