When You Can Use Flex Seal On RV Roof & What’s Better to Use


If you own an RV, you know that maintaining its roof is a crucial part of keeping it in good condition. Over time, your RV roof may develop leaks or cracks that can cause significant damage if left unrepaired. Fortunately, there are products that can help you easily and effectively seal these leaks and cracks.

You can use Flex Seal on your RV roof as a last resort if no other options are available. You shouldn’t use it on a rubber roof. Flex Seal isn’t UV stabilized and is made of silicone, which leaves a residue on the roof that nothing else can stick to, which is why other options could be preferable.

In this article, I’ll explain everything you need to know about using Flex Seal on an RV roof. I’ll discuss its pros and cons and provide a list of alternative products to consider. Let’s dive right in! 

How To Use Flex Seal To Repair an RV Roof

Flex Seal – many use it, many say it’s bad. Is it really only to be used as a quick fix, and why is that? 

Using Flex Seal to repair your RV roof is a simple and effective way to prevent water damage and extend the life of your RV. With just a few steps and patience, you can quickly repair leaks and cracks and keep your RV in top condition. 

However, you should avoid applying it to a rubber roof and remember that you must replace or apply a new coat periodically. 

The steps for using a Flex Seal are as follows:

  1. Clean the area where you’ll apply the Flex Seal. Use a pressure washer on the lowest setting or a hose with a high-pressure nozzle to remove any dirt, dust, or debris. Be sure to let the surface dry completely before moving on to the next step. If you have doubts about using a pressure washer, you can read more about it here.
  2. Shake the Flex Seal can well and hold it about 12 inches (30.48 cm) away from the area you want to repair. Begin spraying in a back-and-forth motion, covering the entire area evenly. Or, if you have the liquid version, you paint or roll it on as described in the product instructions.
  3. Allow the Flex Seal to dry for at least 24 hours before exposing it to water or moisture. This will ensure the sealant has had time to cure and form a strong, waterproof barrier properly.
  4. Once the Flex Seal has dried, test its effectiveness by spraying water on the repaired area. If the Flex Seal works properly, the water should bead up and roll off the surface without penetrating the sealant.

Here’s a quick YouTube video showing how to apply Flex Seal on an RV roof:

The Pros and Cons of Using Flex Seal on Your RV Roof

Flex Seal can be a valuable tool for repairing and sealing your RV roof. However, it’s important to carefully weigh the pros and cons before deciding if it’s the right choice for your situation. 

The followings are the advantages and disadvantages of using a Flex Seal as a sealant on your RV roof:

Pros

  • Easy to apply: Flex Seal is easy to apply and can be used by anyone, even if you don’t have experience with RV roof repairs. It comes in a spray can you can hold about 12 inches away from the surface and apply in a back-and-forth motion.
  • Strong, waterproof barrier: Flex Seal forms a strong and waterproof barrier that protects against water damage and other elements. It can withstand strong wind and harsh weather conditions, making it an excellent choice for protecting your RV roof from the elements.
  • Versatility: Flex Seal is versatile, and you can use it to seal around windows, vents, and other openings in your RV. It can also be used on various surfaces, including metal, wood, and concrete.
  • Quick drying time: Flex Seal dries quickly, allowing you to test its effectiveness in just a few hours. Once it has dried, you can spray water on the repaired area to see if the sealant works properly.

Cons

  • Not UV stabilized: Flex Seal is not UV stabilized, which means it may break down and become less effective over time when exposed to sunlight. This can lead to leaks and other problems with your RV roof.
  • Leaves a residue: Flex Seal is made of silicone, which can leave a residue on your RV roof that nothing else can stick to. This can make it difficult to repair or seal the roof with other products in the future. Here is one of my articles where I explain 7 reasons why not to use silicone-based sealants and what to use instead.
  • Not a permanent solution: As a temporary fix, Flex Seal will need to be reapplied periodically to maintain its effectiveness. This can be a hassle and may require repeatedly climbing onto your RV’s roof to reapply the sealant.
  • Not recommended for use on rubber roofs: Flex Seal isn’t recommended for use on rubber roofs, as it can cause the rubber to become brittle and crack. If you have a rubber roof on your RV, you’ll need to find an alternative solution for repairing and sealing it. Learn more about the 6 different types of RV roofs and how to tell them apart here.

Flex Seal Types and How You Can Use Them on Your RV

Just a reminder that Flex Seal is not on the top of my list when it comes to RV roof sealing products and i think that it should only be used in a last resort when no better option is available.

There are different types of flex seals. Each kind of Flex Seal is best suited for different situations and uses, as illustrated below: 

  • Flex Seal liquid (Amazon Link): This is a thick paint-like brushable sealant that can be applied to various surfaces, including metal, wood, and concrete. It’s easy to apply and dries quickly, forming a strong, waterproof barrier that protects against water damage. Flex Seal liquid can seal leaks and cracks on an RV roof, windows, vents, and other openings.
  • Flex Seal spray (Amazon Link): This product is similar to Flex Seal Liquid, but it comes in a spray can that makes it easy to apply the sealant evenly and quickly. It can be sprayed onto the surface of the RV roof from a distance of about 12 inches (30.48 cm), forming a protective barrier that dries in just a few hours. Flex Seal spray can be used to repair leaks and cracks and to seal around windows and other openings.
  • Flex Shot (Amazon Link): Flex Shot is a mini tube that dispenses a thick, rubberized sealant to apply to various surfaces without needing a caulking gun. It’s easy to use and dries quickly, forming a strong, waterproof barrier that protects against water damage. You can also use it to repair leaks and cracks on your RV roof and seal around windows, vents, and other openings.
  • Flex Seal tape (Amazon Link): This is a self-fusing silicone tape that you can use to seal leaks and cracks on your RV roof. It’s easy to apply and forms a waterproof barrier that protects against water damage. 

Tips for Maintaining and Extending the Life of an RV Roof After Applying Flex Seal

Maintaining and extending the life of your RV roof after applying Flex Seal is an integral part of protecting your investment and ensuring that your RV continues to function correctly. 

Here are some tips to ensure your roof sealant lasts long:

  • Avoid exposing the roof to direct sunlight for extended periods. As stated before, Flex Seal isn’t UV stabilized, which means it may break down and become less effective over time when exposed to sunlight. To protect the sealant, try to park your RV in a shaded area or use a cover to block out direct sunlight.
  • Clean the roof regularly to remove dirt, debris, and other contaminants. This will help prevent the build-up of debris that can cause damage to the sealant and the roof itself. Use a pressure washer on a low setting or a hose with a high-pressure nozzle to remove any dirt, dust, or debris. Be sure to let the surface dry completely before applying Flex Seal.
  • Inspect the roof regularly for signs of wear and tear. Look for cracks, leaks, or other damage that may need to be repaired. If you notice any damage, apply Flex Seal as required to seal the leaks and protect the roof from further damage.
  • Reapply Flex Seal as needed to maintain its effectiveness. Over time, the sealant may break down or become less effective due to exposure to sunlight, moisture, or other factors. Reapply the sealant to strengthen it and protect the RV from leaks and gaps that may be more expensive to repair in the long run.

By following these tips, you can help maintain and extend the life of your RV roof after applying Flex Seal and enjoy a pleasant time in your RV. 

With regular cleaning, inspection, and reapplication of the sealant, you can protect your RV from water damage and other problems, ensuring it continues to function properly for a long time. This can be a lifesaver, especially if you live in your RV.

The Impact of Weather Elements on the Flex Seal on an RV Roof

As you’d expect, weather can significantly impact the effectiveness of Flex Seal on an RV roof. Certain weather conditions can cause the sealant to break down or become less effective, leading to leaks and other problems with your RV roof.

Let’s look at this in more detail below: 

Exposure to Sunlight

One of the biggest impacts of weather on Flex Seal is exposure to sunlight. As earlier stated, Flex Seal is not UV- stabilized and may break down and become less effective over time if exposed to sunlight.

This can cause the sealant to become brittle and crack, leading to leaks and other problems with your RV roof. To protect the sealant, try to park your RV in a shaded area or use a cover to block out direct sunlight.

Extreme Temperatures

Flex Seal is designed to withstand a wide range of temperatures, but extreme temperatures can still cause the sealant to become less effective. For example, extreme heat can cause the sealant to expand and contract, leading to cracks and leaks.

On the other hand, extreme cold can cause the sealant to become brittle and break down, leading to leaks and other problems.

High Humidity

In addition to sunlight and extreme temperatures, moisture exposure can also impact Flex Seal’s effectiveness on an RV roof. Flex Seal is designed to protect against water damage, but excessive moisture can still cause the sealant to break down over time.

For example, if your RV is parked in an area with high humidity, the adhesive may become less effective and must be reapplied more frequently to maintain its effectiveness.

Overall, the weather can significantly impact the effectiveness of Flex Seal on an RV roof. To protect your RV and extend the life of the sealant, it is essential to take steps to mitigate the effects of sunlight, extreme temperatures, and moisture on your RV roof.

With proper care and maintenance, you can ensure that your RV roof remains protected and in good condition.

Alternative Products To Consider for Sealing an RV Roof

Apart from Flex Seal, other better products on the market can be used to seal an RV roof. Some of these options may be better suited to certain situations or may offer unique benefits that make them worth considering. 

Here are some alternative products to consider for sealing an RV roof:

Dicor Roof Coats 

Dicor has various types of RV roof coats that are specially made for applying a protective coat or paint-like sealant, just like Flex Seal, except they are specialized for the different RV roof types. So this would be a better option if you want to recoat your RV roof.

Such as the following:

As you can see, these different products are specially made for your exact RV roof type, and there is a reason for it, so figure out what type of RV roof type you have first and then choose the best product for it; if you are in a pinch and can only get Flex Seal then, by all means, use it but think twice.

On the other hand, if you can use a lap sealant, Dicor has one of the best on the market that I would recommend, or if you are thinking about an adhesive sealant check out SikaFlex!

More on what type of sealants you can use on different RV roof types and how to tell different RV roof types apart so you don’t use the wrong product here in this article.

Dicor Lap-Sealant

This is one of the most well-known products when it comes to resealing RV roofs, although this is not a roof coating or paint-like product; hence it is not meant to cover the whole area of the roof but rather to reseal seams and old seals or around hatches and edges which is what is needed in most cases.

This sealant comes as a self-leveling (amazon link) option, which is meant for horizontal surfaces such as your roof; the sealant will spread out evenly itself within a couple of minutes, so you won’t have to get messy and do it yourself.

It also comes as a non-leveling (amazon link) option which is meant for vertical surfaces where it will stay more in place when you apply it hence you will need to spread it out yourself instead.

A lap sealant is a great product to use for a secondary seal; easy to apply and maintain; you can read more about it and how to apply it here.

Eternabond Seal Tape

Eternabond (amazon link) is a highly adhesive tape that can be used to seal leaks and cracks on an RV roof. It’s made of a unique blend of polymers that provides a strong, waterproof barrier that protects against water damage. Eternabond RoofSeal is easy to apply and can be used on various surfaces.

Although remember that EternaBond is not eternal, and removing it is not funny, which is one of the main reasons not to use it over an extensive area where other sealants may be used, instead, keep some Eternabond for certain emergency repairs or to reseal the top of a slide-out where other sealants would take up to much space and be damaged.

Conclusion

While you can use a flex seal to repair your RV roof, it’s not advisable, and you’re better off using other alternatives, as discussed in this article.

It’s important to note that Flex Seal is not explicitly designed for use on RV roofs. It is a heavy-duty adhesive marketed as a solution for quickly and efficiently repairing leaks, holes, and gaps in various surfaces. However, it is not a long-term solution for repairing or sealing an RV roof, and it may not effectively address all types of RV roofing problems.

Sources 

Rikard Adamsson

Hello! My name is Rikard Adamsson; I am the creator of Motorhomeking.com. I live full-time in my motorhome, and right now, I am traveling through Europe the right way, without campsites; yes, wild camping and being off the grid works excellent even in a real beauty from 1996. I have done a lot of rebuilding and upgrades. I am happy to share my experiences with everything regarding motorhomes, RVs, or caravans with you here at motorhomeking.com.

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