Best Rv Sealant For Windows And Seams Exteriors

We have tested six different RV sealants that you can use to seal off your RV’s windows and exterior seams, and we have found that Dicor Lap Sealant is the best overall.

Keeping your windows and exterior seams sealed is essential to ensure that your RV does not sustain any damage due to weather or water. However, not all sealants are suitable for all purposes, and there can be a lot of conflicting information online.

Luckily, you can look for some specific things to determine whether or not a particular sealant will be suitable for the use you have in mind. It is essential to ensure you read up on the pros, cons, reviews, and other aspects of a sealant before making your final purchase. Buying the wrong sealant can cause you to lose money and time and cause more damage.

1. Dicor lap SealantBest Overall

2. Sika Sikaflex-221 Best For Windows

3. Dynatron Auto Seam SealerBest For External Seams

4. Geocel 28100V Pro FlexMost Diverse Application Conditions

5. Alpha Systems RecPro Non-SagBest For All Weathers

6. Alpha Systems RecPro 4 Pack 1010 Non-SagBest Value

Dicor Lap Sealant is one of the most highly recommended sealants for RVs and is the best one to seal exterior seams and windows. This sealant is easy to apply with a caulk gun and isn’t self-leveling, meaning that it won’t run down your seams, but keep them sealed. This sealant is also very versatile and can go on almost all RVs.

Naturally, these aren’t the only reasons we prefer this sealant. To find out more understand why we feel this way, keep reading.

The 6 Best RV Sealants For Windows And Exterior Seams: Product Reviews

1. Dicor Lap Sealant – Best Overall

Dicor’s Lap Sealant comes in an easy-to-use 10.3-ounce tube that you insert into a caulk gun to apply the sealant anywhere you need it. This sealant is not self-leveling, making it great for horizontal and vertical surfaces such as seams and window gaps.

This sealant is also compatible with almost every type of RV surface, making it great for sealing seams, and it is also good to seal windows. This sealant remains flexible over time, meaning that it will expand and contract with the RV to avoid it coming loose in time.

Overall this is an excellent sealant for almost all uses and we, like others, recommend it highly.

  • This sealant is non-sagging, making it great for vertical applications
  • This sealant is easy to apply
  • This sealant is suitable for almost all surfaces
  • The price of this sealant is too high for some
  • Some complain that the tube might break

2. Sika Sikaflex 221 –  Best For Windows

Sika Sikaflex is another suitable all-around RV sealant, but we recommend it for sealing your windows as it is both a sealant and a flexible adhesive. Sika Sikaflex comes in three different colors, and if you do not find the color you want, you can sand and paint over it.

The 10.1-ounce tube that this sealant comes in also makes it easy to use once loaded into a caulk gun. The thin tip also means that you can get into any smaller areas or gaps to ensure that your window is properly sealed and will stay in place.

This sealant is also fast drying, drying in as little as two to three hours, though you should leave it overnight to cure fully.

  • This sealant dries quickly
  • The tube this sealant comes in makes it easy to use
  • There are multiple color choices
  • This sealant is very affordable
  • The tube has to be “corked” to stop the sealant from drying
  • Some people have reported the wrong color in the tube

3. Dynatron Auto Seam Sealer – Best For External Seams

Dynatron Auto Seam Sealer is a sealant that prides itself on staying in place while still easy to apply. We recommend this sealant for all your RV seams as the application process is easy, the adhesion levels are high, and the skinning starts fast.

This sealant comes in a 12-ounce tube that is easy to load into a caulk gun, and by using a brush, you can easily spread the sealant to be where you need it. This sealant is also flexible, meaning that it will expand and contract with the rest of your RV to help it last longer.

Though this sealant comes in a grey color, it does not stain, and since it does not run, there is little chance of it spreading to an unwanted area.

  • The skinning process starts quickly
  • The application is easy
  • You can easily apply this sealant with a brush
  • The sealant comes in a grey color
  • The tube does not have a sealing cap

4. Geocel  Pro Flex – Most Diverse Application Conditions

The Geocel Pro Flex sealant comes in an easy-to-use 10-ounce tube and is easy to apply. This sealant sticks to almost any surface, and application can take place on damp, slightly oily, or frozen surfaces making it very diverse and great to have in bad weather conditions.

This sealant is also clear, and you can paint over it to help it blend into the color of your RV. We recommend this sealant because you can apply it to many different surfaces even when the weather conditions aren’t favorable.

This sealant is a bit expensive, but most others that have used it have given it high praise, and it boasts the label of Amazon’s choice of RV sealant.

  • The application process is simple and diverse
  • This sealant is clear, making it great for any color
  • This sealant is quite pricey
  • This sealant can make a mess if you are not used to it

5.Alpha Systems RecPro Non-Sag– Best For All Weathers

Alpha Systems made the RecPro Non-sag sealant specifically to seal up any gaps or areas on the side of your RV or any other vertical sites. With a one-year shelf life and a resistance to most types of weather, you can’t go wrong with this sealant.

This sealant can also handle a wide range of temperatures from -40 to 250 degrees Fahrenheit, meaning it will expand and contract along with your RV. This sealant is excellent for all your sealing needs with its weather and temperature resistance and the no-sag feature.

This sealant is also white when dry and comes in a tube used in a caulking gun. The size of the tube is 11 ounces.

  • Made for vertical application
  • 1-year shelf life
  • Highly weather-resistant
  • This sealant can be pretty messy to apply
  • There is often no date on the tube to show you the shelf life

6. Alpha Systems RecPro 4 Pack 1010 Non-Sag – Best Value

If you are looking to make only one purchase to use on many occasions, you can’t get any better than the Alpha Systems RecPro 4 Pack. As seen above, this sealant is resistant to most types of weather and can withstand a wide range of temperatures.

This four-pack includes four identical 11-ounce tubes of this sealant, and this sealant was explicitly designed for vertical applications such as outer seams and windows.

These tubes have a shelf life of 1 year, and all the tubes included in the purchase are white though you can paint over the sealant if you wish. It is essential to note that we only recommend buying this deal if you have a big job ahead of you.

  • The sealant dries white and is paintable
  • The price for 44 ounces is reasonable
  • There are a lack of dates on the tubes to show shelf life
  • The application process can be tedious and messy

Buyer’s Guide

Knowing tips, tricks, and what to look for before buying a sealant for a specific job is crucial. If you buy the wrong kind of sealant, you might end up wasting money or could cause damage to your RV and give yourself more work. We always advise you to research a product before making your purchase, and reviews can also be helpful.

The Area Of Application And The Type Of Sealant

Almost any sealant compatible with your roof type will suffice for sealing gaps around your RV’s sunroof. However, for windows, seams, and other vertical applications, you have to be sure to buy the right kind.

It is essential to make sure you buy a sealant that will not run down your RV but can be applied to the area and will stay in place. Self-leveling sealants are usually runnier and will generally not remain in place if used on a vertical surface. That trait makes the self-leveling type the wrong sealant for this use.

There are, however, sealants explicitly made to stick to the side of your RV and remain in place. These sealants are more commonly applied with a brush or trowel to ensure they are in place. These sealants are usually not runny, and the packaging might call them sealants for vertical use or non-leveling and non-sagging.

The Benefits Of The Sealant

There are naturally other things that you will also consider when buying a sealant for a specific job. Some sealants come with added benefits like specific colors, materials, or eco-friendliness. These aspects might not be on the top of your list for things to look at, but they can be very beneficial.

For example, finding a sealant that is the right color to blend with the rest of your RV will naturally make it look a lot better than a color that is off. There are also benefits, like some that you can sand over the sealant or apply more over the original application. These aspects can be beneficial, especially in the long run.

The Ease Of Use

Ease of use is another essential aspect, even if it does not seem important. The fact of the matter is no one wants to struggle and spend hours on a job that could last only 20 minutes.

Finding a sealant that is easy to apply for your specific purpose can be tricky if you have not tested it out first, but we recommend looking for a sealant that comes with an easy-to-use nozzle and can be applied using a brush or trowel. Here is a video from YouTube to demonstrate how simple it can be to apply a sealant to your RV windows.

It could also be in your best interest to read some reviews on the matter to see if the compound container might break. Though a breakable container should not put you off from buying a suitable sealant, it might help you prepare if the same happens to you.

The Sealants Resistance To Water

The number one reason for using a sealant anywhere on your RV is keeping water out and keeping your RV in shape. It is crucial to ensure the sealant you buy is water-resistant and will not come loose after one night of rain.

Silicone sealants are notoriously bad at staying in place after a storm or even after some light rain. For this reason, we recommend using a sealant that does not consist of this material.

It is essential to ensure that you buy a sealant that can stick even in rainy weather since this is the main reason for needing to seal your RV. You do not have to buy a sealant that can be applied in all weather conditions, though this might also be beneficial.

The Elasticity Of The Sealant

To seal any part of your RV, the material you use needs to grow and shrink as the RV does. This aspect of a sealant is essential to keeping it in place and doing a good job. If a sealant hardens too much, it might crack, break, or come loose when the materials around it expand and contract.

As with other aspects, you must ensure the sealant you buy will be able to expand and contract as it should. If the sealant you buy does not do this, it might break or detach, giving you extra work and wasting money.

The Reapplication And Painting Process

Some sealants consist of materials that make it impossible to apply another layer over them. This aspect is crucial to consider as it means you will have to remove the sealant entirely before being able to use a new sealant over it.

No matter how good a sealant is, you will always have to apply another layer in time on an RV. For this specific reason, it is necessary to ensure that the sealant can be worked over or removed easily. Even when the sealant is still doing as intended, some become dark, dusty, and don’t look nice. Knowing you can easily apply a new layer over a dirty one can save you time and effort.

Another aspect to consider is the color variant of the sealant and whether you can paint over it. If you cannot paint over the sealant you use, you should be sure to buy a color that you will be happy with using. Sealants will often state whether you can paint over them or not, so be sure to keep an eye out for this information.

The Price Of The Sealant

The price of a sealant can make or break your expectations, and for the most part, they work similarly. Naturally, brand names cost more, even in the RV repair world. However, there are many suitable replacements that you can find if you know who to ask or where to look.

It is essential to measure the price of a sealant compared to the benefits and uses of a sealant. Doing this means that you will avoid disappointment, and you can also save some money by finding a similar sealant that costs less.


Considering all the factors and considerations we have mentioned above, the best sealant for sealing around your windows or your exterior seams is Dicors Lap Sealant. You must ensure you buy the non-leveling variant as there are two available, and the self-leveling version might not work or run down.

Dicor’s non-leveling lap sealant will stay in place when applied to vertical surfaces, which means less mess and less frustration. This lap sealant is also easy to use for your RV, and though there are complaints about the quality of the tube, they are not very common.

This lap sealant is also compatible with almost every different material used on RVs, which means that it will stay in place and seal off any of the gaps or leaks you might have.

Dicor Non-Leveling Lap sealant is available to view and purchase on Amazon.

Good luck, and happy camping!

Check out our article on: Best Rv Roof Sealant For Aluminum, Rubber, And Fiberglass Roofs

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