Rust-Oleum Leak Seal vs Flex Seal (Best Option for RV Roof)

Let me tell you this: leaks suck.

You probably want to avoid having your RV trip literally rained in on, so before you set out on a road trip, it's important that you are prepared for dealing with any leaks on the road.

Leaks happen, but they don't have to ruin your life.

Fortunately, a company called Rust-Oleum happens to make two very good products that are excellent at fixing leaky things: Leak Seal and Flex Seal.

But between leak seal vs flex seal, which is better and which one should you use? Learn more here!

Leak Seal vs Flex Seal: is there a clear winner?

Both Leak Seal and Flex Seal are uniquely suited to specific uses as you’ll see below, so it’s hard to call a winner.

However, if it’s durability you are concerned about, there is no doubt that Leak Seal is far more durable and long-lasting than Flex Seal. The rubberized sealant is very durable and robust, and you won’t need to redo the seal for a very long time after applying it.

What is Leak Seal?

The first product that we are going to talk about today is Leak Seal. For first time RV owners, this is an incredibly popular liquid rubber sealant.

What makes this product such a popular option is that it can help to close any significant leaks or cracks at any moment during a road trip incredibly quickly.

Depending on where the leak may be, an individual can spray the liquidized rubber onto the targeted area and then the magic of Leak Seal will take over.

This specific product does well in all climates and environments, helping to prevent any additional leaks or cracks.

Surfaces Leak Seal works on

  • Wood
  • Metal
  • Glass
  • Masonry
  • Cement
  • Concrete
  • Certain types of plastics
  • Vinyl
  • Rubber


  • This is a great product for individuals that are not experienced in sealing up leaks. It?s relatively easy to use and dries quite fast!
  • Leak Seal performs great in all climates and environments. Whether you are planning a road trip during the winter or through the desert in the summer, this sealant can rise to the occasion.


  • If an individual is not careful when applying the sealant, it can prove to be ineffective. It?s critical to apply at the perfect angle
  • Many RV Owners have complained that leak seal can be difficult in the beginning, especially when maneuvering the can in tight spaces.
  • This material cannot tolerate gasoline. If the sealant is exposed with gasoline, it will erode and dissipate.

What is Flex Seal?

On the other end of the competition stands Flex Seal. This is another liquid rubber sealant that has proven effective at helping to seal any crack or leak.

What makes flex seal a popular option among consumers is that it does a great job at preventing any water from seeping in our out of the target location ? and can last for a while if taken care of properly.

This product performs best in room-temperature environments, rather than extreme climates. Applying flex seal, as we will discuss later, is not rigorous, but will require some care and attention.

Surfaces Flex Seal is Compatible With

  • Wood
  • Metal
  • Glass
  • Masonry
  • Cement
  • Concrete
  • Certain types of plastics
  • Vinyl
  • Rubber


  • Flex Seal does a great job at preventing any further leaks, cracks, corrosion, or rust.
  • This sealant is optimal for nearly any surface. Whether you are needing to cover a crack in vinyl or on wood, this product can help.
  • What makes Flex Seal a great choice for some RV owners is that it?s easy to apply and quick to dry. You will not need any additional equipment for application.


  • Depending on the size and severity of the leak or crack, an individual may need to apply multiple coats and treatments of Flex Seal to close the area.
  • This can will require some unique maneuvering, which may make the owner uncomfortable.
  • Flex Seal does not perform well in extreme environments, including hot or cool temperatures. In fact, the rubber can wear and tear quicker, requiring new applications.

How to apply Leak Seal and Flex Seal

One of the biggest mistakes that we all make when using a sealant like a leak seal or flex seal is that we do not properly follow the application instructions. In truth, there is a method that must be followed for the absolute best results.

Now, if this is your first time using either of the two products, it?s important that you understand exactly how the product functions and what?s required of you.

With that being said, it?s critical that an RV owner takes the time to clean up the area where the leak is prevalent before applying any leak sealant.

This means removing any major debris, drying the target area, or removing any rust that may prevent a clean and seamless application.

From there, it will prove beneficial to carefully clean the surrounding areas as well.

 Once the area for application has been treated, you can proceed forward with applying in accordance to the bottle. Spray smoothly and evenly for proper distribution.

Now, the process does not stop there. 

You see, it takes quality time for the actual product to essentially close the leak. In fact, depending on the quality of the sealant, it may take, at a minimum, 24 hours.

During the drying period, it?s highly suggested to allow for maximum breathability and ventilation. In this, avoid tending to the area, unless you plan to apply a second coat. In this case, each coat should be applied within 30 minutes of each other.

Is Leak Seal or Flex Seal more durable?

As we have already depicted, leak seal and flex seal are gravely different products, even though they have similar goals.

Now, before any RV owner purchases any product for their mobile adventure home, they should always consider the durability of the product they are purchasing. When it comes to leak seal and flex seal, it might be shocking to learn that these sealants do not offer the same degree of durability and strength.

In fact, out of the two products, leak seal has received praise and built a reputation as the strongest sealant for RV owners. If applied properly, Leak Seal can withstand any weather extreme, including hot and humid temperatures or even the frigid winter storms

Flex Seal, on the other hand, is prone to problems given the environment and climate it?s in. For example, a leak that was patched with flex seal may re-open in hotter, drier temperatures, like a desert.

So, depending on what type of travelling you are planning on doing, it may influence your decision as to what sealant is best for you. However, do keep in mind, if the rubber from a sealant, like Flex Seal, is removed during traveling, you can always replace it by reapplying the sealant.

Frequently asked questions

Can I use Leak Seal and Flex Seal on my RV Roof?


While you can use both for your RV roof, it’s best to use Leak Seal as it’s more durable and weather resistant.

Does Leak Seal or Flex Seal work for gas tanks?


Leak Seal and Flex Seal don’t work for gas tanks, as gasoline causes the material to deteriorate.

Can I use Leak Seal or Flex Seal for toilets?


Both of these sealants are great for toilets, but just make sure the area is completely dry before you apply the sealant. Then let it dry for the recommended period, and you’re good to go.

Are Leak Seal and Flex Seal food safe?


Leak Seal and Flex Seal are not food safe, not even for pets. Do not use these sealants for anything that comes into contact with food.

How long does it take for Leak Seal and Flex Seal to dry?

The initial coat will dry in about 4 hours, but it takes about 24 to 48 hours to fully cure. Let it fully cure before exposing it to the elements for full effectiveness.


Now, at this point, you might be wondering, what?s best for RV owners? n truth, after spending countless hours evaluating and experimenting with both Leak Seal and Flex Seal, we can say, with confidence, that it?s challenging to say what is the best product.

Both of these sealants bring a wealth of advantages and solutions for RV owners. With that being said, if you are looking for maximum protection before your next road trip, we think that all RV owners should carry a can of both Leak Seal and Flex Seal.


Well, keep in mind, flex seal is not an optimal choice for exterior use because of its lack of weather resistance. So, flex seal will prove to be more beneficial for fixing any leaks on the inside of the RV.

Leak Seal, on the other hand, can help to handle any leaks that occur on the outside of the RV, given its natural durability and weather-resistance properties.

2 thoughts on “Rust-Oleum Leak Seal vs Flex Seal (Best Option for RV Roof)”

  1. The core idea of RV camping is to get together with family members and create cherished memories. Create a memorable travelling experience and make your entire family involved. This is your trip do things you enjoy doing the most. Happy camping! Please don?t forget to read out my blog and give reviews.

  2. Instead of using ordinary sealants, I recommend using Liquid Roof. Liquid RV Roof is a one coat system for your RV. The result is customers saving labor costs and material costs since many of the other systems on the market require multiple coats and provide no warranty.


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