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Best Roof Sealants to Repair a Leaking Roof

A roof is ideally your first line of defense against many elements, which means that it constantly takes the beating of rain and harsh sun so you don’t have to. And they will huff and puff, and eventually cause cracks and breakages. Through this repeated process, even the toughest of roofs eventually cave into the forces of nature, but there is a solution to this – roof sealants.

Roof sealants have been around for the longest time, used by our forefathers and their fathers to increase the lifespan of your shingles and roofing tiles alike. Sealants act as an extra barrier between your roof and all the rain, sun, fire and ice. They are made using elastomeric material which keeps them flexible to expansion and contraction, such that they hold up for longer. One may argue that modern roofs are made to last long. Indeed they are, but constant exposure to rainstorms and sun eventually causes a significant decline in their lifespan.

Sealants make the ultimate sacrifice by taking the burns instead of your roof; they have insulation properties too and hold back the growth of mold and algae. Needless to say, you will need a sealant that is able to live up to all this, which is why we have compiled a list of the best roof sealants out there today.

Top 10 Roof Sealants of 2020 Reviewed

1. Dicor RP-CRC-1 Rubber Roof Acrylic Coating

    Best Roofing Sealant for RV

    Our topmost sealant claims its position by being one of the highest quality sealants in the market. It comes to you as the second phase of a two-part system. This means that for best results, you should first apply a rubber roof cleaner beforehand, and then add the coating after that for an overall better adhesion.

     

    Dicor RP-CRC-1 Rubber Roof Acrylic Coating Wht

     

    Dicor works by forming a protective barrier on your rubber roof’s membrane using its elastomeric feature (elasticity and flexibility). By so doing, it is able to hold up in areas where your roof experiences movement without causing any breakages. What you get with this coating is a definite increase in the beauty and lifespan of your roof; it’s perfect for retrofit installations.

    The coating also prides itself with its proven ability to resist harsh weather conditions and ultraviolet light. With its superior fire retardation characteristics in place, Dicor should be safe for use in a rocket ship.  Two coats are necessary for better protection yet despite this; it has been proven to save up to 25% in labor when compared to other products. Maybe this might have something to do with its quick-drying capabilities.

    Pros
    • Offers UV protection
    • High flexibility and elasticity
    • Dries quick
    Cons
    • Requires application of two coats
    • Requires prior application of a cleaner
    • Waiting time between coats may be lengthy

2. Liquid Rubber Waterproof Sealant

    Best Roofing Sealant for Home Restoration

    Unlike most other sealants, the liquid rubber waterproof sealant stands out with its relative ease of use. Its application is basically like painting only that it involves heavier coats which aid in the overall buildup of a waterproof membrane. The sealant also boasts in its environmental friendliness. It is purely water-based, with no solvents or VOC’s present. This means that you can safely use them both indoors and outdoors without the need for breathing apparatus. By this, you also get to guarantee the safety of your children and pets.

    Liquid Rubber Waterproof Sealant

    The liquid sealant comes as a by-product of bitumen and various polymers, which work together to form a high quality elastomeric and waterproof membrane. This guarantees its effectiveness against all of the elements. It is non-flammable and fully compatible with polystyrene or polyurethane insulation materials.

    Liquid Rubber sealant is also stable with a 100% elongation; enough to stand tall in the face of the sun without the possibility of degradation. You can use the product on any type of rood too, including planter boxes, gutters, ponds, mobile homes, wood, meal and sheds. For an even more bulletproof effect, you can bridge the seams or where movement may occur with additional liquid rubber seam tape.

    Pros
    • Easy to use
    • Environmental friendly
    • Fully waterproof
    Cons
    • Relatively costly
    • 5-gallon size may be too much for small area usage
    • Takes time to cure in cold weather

3. Jetcoat Cool King Elastomeric Acrylic Reflective Roof Coating

    Best Roof Sealant with Reflective Properties

    The Jetcoat Cool King brought to you by retail giant Jetcoat, is an Acrylic type, reflective Roof Coating. So to speak, it is able to do everything a roof sealant can.  This includes the elastomeric properties in place, which allow it to stretch, and act as a rubber-like membrane over your roof’s surface. The coating also reflects the sun’s rays, so you can get to save all those extra costs in air conditioning. It will work well on different surfaces, including wood, metal, masonry and asphalt.

    Jetcoat Cool King

    For best results, you are advised to apply the coating using a soft brush, high-pressure sprayer or nap paint roller. You can add a second coat too for more durability and performance. Through testing, the cool king is estimated to last as much as 5 years on proper application, so you can forget about the hustles of adding protective coats every other year.

    The coating should be applied on a clean roof, free of any debris, dirt or other foreign material. It dries pretty fast too; Cool to touch within only 2-4 hours, although you are advised to wait 6-8 hours before applying a second coat. One gallon of this coating covers as much as 50-70 square feet.

    Pros
    • Long-lasting(up to 5 years of protection)
    • Elastic in nature; great coverage
    • Easy to wash off with water
    Cons
    • You might need a second layer for best results
    • Some users claim the product is a bit thin; might need more than 2 coats

4. Dicor 501LSW-1 Epdm Self-Leveling Lap Sealant

    Best Self Leveling Roof Sealant

    This is yet another highly valued sealant in the market. With its rubber design, the Dicor 501LSW-1 EPDM Self-Leveling Lap Sealant is ideal for sealing RV roofs, or any other motor vehicle roof. Perhaps the most outstanding property about this sealant is its ability to level itself on application. With this, you won’t need to use a brush or roller, simply squeeze it out and it melts out over the surface.

    Dicor 501LSW-1

    Yet another eye-catching feature in the Dicor is how it is able to create watertight seals. Safe to say, you can use it around all your screw heads, air cents, cent pipes, air conditions and along the edge of your roof. This is surely bound to come in handy sometime.

    The sealant can also be used in sealing EPDM and TPO sheets because it is also duly adhesive to other materials such as mortar wood, aluminium, fiberglass, galvanized material and even vinyl.  It is also a user favorite when sealing metal or concrete. Another feature that makes this product convenient is its ease of use. The Dicor comes in a 10.4 oz tube which you simply squeeze out the sealant, and it selectively applies on your required surface.

    Pros
    • Works well with EPDM sheeting
    • Has a white finish
    • Comes in an easy to use 10.4 0z tube
    Cons
    • Some tubes come with super thick content which may not really self-level as advertised
    • Sometimes the nozzle comes damaged
    • The small packaging may not be convenient for large surface area use

5. Liquid Rubber RV roof coating sealant

    Best Water Resistant Roof Sealant

    If you are looking for a sealant specifically suited for your RV, then you have found your match. Other than the fact that it has RV in its name, this sealant is also good for other mobile homes like trailers, as well as for use around the home on sheds, gutters, wood, metal, concrete and sheds. It has elastic properties in place which make it suitable for moving parts.

    Liquid Rubber

    The sealant is liquid in nature, though it will dry up to form a firm water-resistant membrane when exposed to air. Apply heavy coats for a more waterproof membrane effect and if you only need it for a small section, you can close the lid and save it for a later date (it won’t dry out). 

    The sealant works best in dry conditions, on surfaces free of coatings, grease, and other contaminants. Typically, it will fully cure in 24 -48 hours. Since its, water-based, it does not contain any solvents, meaning it’s perfectly environmental safe and user-friendly. It comes in white and easy to apply; simply user a brush or sprayer. We can’t go without mentioning its rather impressive coverage of 1 gallon per 50 square feet. Meaning with 2-3 heavy coats, it will cover as much as 50-foot RVA roof.

    Pros
    • wide coverage
    • creates a fully waterproof membrane
    • environmental friendly
    Cons
    • takes a relatively long time to cure
    • you might need to transfer it to smaller sized buckets for easier use
    • needs 2-3 coats; you have to wait for it to dry after each coat application

6. Flex Seal Liquid Rubber in a Can

    This next product prides itself in being one of the longer-lasting sealants on our list. The Flex Seal Liquid Rubber in a Can will come in handy for when you need a flexible, yet waterproof rubberized coating for your roof. Due to its liquid nature, it is smooth to apply with a roll or brush. Its proprietary formulation then works by starting out as being a thick liquid, then drying quickly to a strong, watertight, yet flexible rubberized coating. This coating easily seals out all the air, water and moisture from your surfaces.

    Flex Seal

    The sealant is made from fully non-toxic, non-hazardous and non-flammable material. It is also UV-resistant, so you are guaranteed the extra protection against the sun’s rays. All this yet it still holds up against any form of corrosion, rust, chemicals or mildew. Flex is also paint-friendly, meaning. Once dry, you can add on the paint of your choosing.

    Pros
    • Can be painted any color once dry
    • Good for use on leaks
    • Easy to apply yet Fully waterproof
    Cons
    • Might take longer to cure for more durability
    • Extremely slippery when wet
    • Considered expensive for its size of can

7. Rubber seal Liquid Rubber

    Rubber Seal Liquid Rubber is one of the cheaper yet surprisingly effective alternatives you will find out there. It uses liquid rubber, which means you can trust it to be equally flexible on drying and fully waterproof. This makes it applicable as a protective coating and for sealing cracks or leaks on your roof. It also has insulating and ceramic properties which will keep your roof airtight and free from the sun’s heat penetration.

    Rubberseal Liquid Rubber

    Having an EPA Energy Star Rating, you are assured that the product is UV resistant and resistant to ageing, meaning the sealant will support you in the long haul. It contains very low levels of VOC and excellent elongation properties. With this sealant, the process of application is a breeze; this might have something to do with its outstanding spread rate of 60 square feet per gallon at 20 imperial mils.

    Pros
    • Nicely waterproof
    • EPA certified; fully UV resistant
    • Quick spreading rate
    Cons
    • Some users claim it can take as much as 5 days to cure fully
    • Its white color is prone to discoloration
    • Is a little thin; may need more than one coat

8. Heng’s rubber roof coating

    If you are looking for a crack-resistant quality coating for your roof, the Heng’s rubber roof coating is the one for you. Made using 100% acrylic latex polymer, Heng’s is excellent for any kind of EDPM rubber roof. Its material makes it especially resistant against impact, which is the main factor that causes cracks. This also has something to do with its ability to conform to the particular nature of your roof. It expands when exposed to heat and constricts in the cold.

     

    Like most high-quality sealants, Heng’s is UV resistant and is made from non-toxic materials which are safe for consumers. In addition to this, it boasts of excellent insulation and acoustic properties to protect you against the suns heat. When it comes to drying time, Heng’s only takes 1-2 hours to be fully dry to touch.  You are however advised to give it at least 4 hours before applying the second coat and an extra 24 hours for full curing after that.

    All in all, the coating is good for RV rubber roofs, tears and seams as well as RV vents and air conditioners.

    Pros
    • Crack and impact resistant
    • UV resistant
    • Quick drying
    Cons
    • Some users claim their cans came damages/ deformed
    • Might need extra coating after a year or so
    • You’ll need to fully clean surfaces before applying, or it will peel off

9. Loctite PL S30 Black Roof and Flashing Sealant

    The best way one would describe the Loctite PL S30 Black Roof and Flashing Sealant is as a premium quality sealant developed for commercial use. The sealant’s polyurethane formulation allows it to form permanent, all-weatherproof seals in exterior gaps and joints.  For this purpose, Loctite is both elastic and flexible to expansion and contraction for extra protection of the original seal.

    Loctite PL S30 Black Roof and Flashing Sealant

    With this easy to use sealant, you get permanent protection against corrosion. It has been tested and proven to withstand the trials of time; holding up against tears for long periods of time despite exposure to the elements. The sealant also works independently, without the need of a primer. Because of its qualities, it is perfect for expansion joints, and if you want it to blend in with your surfaces, you can paint on it too.

    Pros
    • UV resistant
    • Weatherproof
    • Requires only one-time application (no primer needed)
    • Low VOC formula
    Cons
    • Comes in small packages that may not be suitable for a broader surface
    • Mostly meant for small tears and cracks
    • Exposure to air may cause it to dry in its pack

10. HENRY HE587372 Roof Coating

    With every purchase of the HENRY HE587372 Roof Coating, you get a 5-gallon adhesive bucket of awesomeness. Despite being number ten on our list, this white roof coating comes ready to impress. With features such as its easy to use kit that will make your coating experience seamless. Every application results in a thick layer, with high insulation properties. In fact, some users have attested to the product lowering your roofs temperatures by as much as 40 degrees.

    HENRY HE587372 Roof Coating

    The Hendry also has relatively good pricing. It can be used on near every roofing material you throw at it and if you follow its application instructions to the latter, it will leave your roof brand new and cool. Speaking of application, you might need to wear sunglasses when applying on a sunny day, because of its high reflective qualities, which only stands to prove of its immediate effectiveness.

     

    The coating is also made from an elastomeric material, which allows room for elongation and when the coating has cured fully, it allows room for moisture or vapor to breath out of any underlying substrate or vent.

    Pros
    • Relatively cheap
    • Highly reflective of the sun
    • Elastomeric material
    Cons
    • Needs as many as three coats to get that thick, durable effect.
    • Curing process takes long
    • 5 gallon may be much for a small roof

How to Choose the Best roof sealant: The Ultimate Buying guide


 After looking at our top selection, it might still be hard to choose a roof sealant, especially if you don’t really know the difference between types and what some of these terms mean. We have done a comprehensive buying guide to help you gain a better general understanding of roof sealants, and help you choose the best one for your particular need.

What is a roof sealant; how does it work?

A roof sealant is kind of like a mix between varnish and paint. It works by sealing up holes and cracks which might be forming on your roof, air vents, and air conditioning units. They have a strong adherence to your particular surface as well, which makes them especially strong. Most of them will also do well to make your vehicle additionally resistant to environmental impacts, such as rain and snow, which can cause the formation of cracks and holes on our roof.

What is your purpose of sealing; what benefits do I get from sealants?

Sealants tend to pose many different qualities that will overall improve the quality and lifeline of your roof. Some of them include;

  • Structural protection for your roof

This is the most common reason why people purchase sealants. They not only help seal up any cracks already on your roof, but they also help prevent the occurrence of new ones. That said, a sealant will help maintain a stronger structure for your roof, save it from the adverse effects of the elements and ultimately, save you money from all those costly roof repairs that would otherwise come about.

 

  • Temperature regulation; retain that smile through the seasons

The roof sealant acts by forming a protective barrier around your roof. With its UV regulation and sunlight reflection properties, this would mean cooler overall internal temperatures in the summer and warmer winters. With this, you can save those extra costs on your power consuming Air conditioning.

 

  • Reducing wear and tear on your roof

Your roof is arguably the first line of defense against attacks by the elements. It takes a lot of beating over time, which eventually results in wear and tear. With a rubber sealant providing that extra layer of protection, the wear and tear will be reduced to a bare minimum, resulting in far longer roof shelf life.

  • Reducing costs

A roof is the most susceptible when it comes to passive damages over time. It is also the one that would require the most immediate attention when it comes to repairs. With a good sealant in place, you can rest assured that the structure of your roof is stronger and more resilient to damages. And what does this mean exactly? You guessed it – fewer demands when it comes to maintenance costs. This goes without accounting all the small extra costs you’ll save on temperature regulation and the like.

Types of roof sealants; which is best for my need?

Urethane coating

This is arguably one of the more durable choices in the world of roof sealants, which is perhaps why it’s also a popular selection among roof owners. It has a tough structure, which makes it especially good in offering protection against small debris and falling branches as well as keeping it free from damage against the elements. Because of this, it is considered to be more efficient in the long run than acrylic kind of coating. It’s important to note that Urethane will tend to take up more application time and cost because it requires you to put at least two coats for it to work effectively. They are also more pungent during application.

Acrylic coating

Acrylic coatings are good solutions when it comes to quickly stopping gaps. They are also among the cheaper roof sealants out there. These coatings are ideal for already damaged roofs because they help prevent further damage while still reflecting sunlight. So if you happen to have any leaks on your roof, this type of coating would be the best in keeping out the water. The only downside is they take a lot of effort and time to apply and generally don’t last as long as others.

Silicon coating

Silicon is relatively the most expensive alternative out there. As you might guess, it also happens to be the most durable. Silicon coatings work well to prevent degradation from the elements like the wind sun and ponding water. It has a very elastic structure, which allows it to remain intact over longer periods of time. This also leaves it less brittle over time, and less prone to crack.  It’s important to note that due to its white coloring. Silicon tends to get dirty or discolored faster and might need regular washing to maintain its state.

Key features you should consider

The best type of sealant for your type of roof

First of all, you should keep in mind that the coating and sealants are two different products that would serve you differently. If you are looking for something that insulates your roof, adds structural integrity and prevents damage from weather conditions, you’ll need a coating. On the other hand, if you want to fix leaks and cracks and other patchworks on your roof, a sealant would be the preferred alternative.

That said, there are five major types of roof sealant, each of which is made for a particular make of roof. Firstly, we have aluminum coatings, which, as the name suggests, were used more traditionally on aluminum roofs. Nowadays, aluminum roofs are extremely rare because they are heavier than most other materials. These types of roofs, however, need less maintenance on the surface, meaning they will mostly require caulking around penetrations.

Next up is fiberglass coating, meant for fiberglass roofs, but, as the former, it is not as commonly used today because fiberglass tends to oxidize more.  They do well with clear coat sealants.

Liquid Coatings and Roof Caulking

Thirdly, we have liquid coatings, which are more polymer-like, comparable to car wax. Coming fourth are rubber coatings, which are considered the most common and preferred sealant today. Rubber coatings will work well with any modern RV or mobile housing; since most modern roofing are made of rubber-type. When it comes to rubber-type roofs, the best, like EPDM (Ethylene Propylene Diene monomer), comes with UV protective properties already, which make them last longer. Over time they tend to get a chalky appearance due to oxidization. We also have TPO roofs (Thermal Poly Olefin), which are still rubber roof types but are more rigid than EPDM.

The last roof sealant type is roof caulking. Caulking is a common term that mainly refers to sealing cracks or any kind of penetrations in order to prevent water leakages.

Formulation; the material of sealant that is best for your need

The material of your sealant will make a huge difference in its overall performance. This can either be liquid sealants or tape sealants. Here, Liquid sealants are better suited if you are looking for elasticity. The formulation does a lot to determine the quality of the product. As of now, the best and most preferred material when it comes to weather resistance is silicon. However, urethane and acrylic also do well to serve their purpose.

The formulation also dictates the type of surface the sealant can be applied. Not all sealants will be suitable for fiberglass while others won’t be good on rubber. However, Most of the products on our list are rubber coating in type, which will well suit most types of surfaces.

Durability; because longer is better

There are many factors involved in assuring the durability of a roof sealant.

  • Elasticity

First of all, you will probably need a sealant with adequate elasticity. Sealants are composed of many different compounds, which, after application, result in different levels of elongation. Since your roof tends to flex and twist with movement, your sealant should be able to hold up, while still retaining its resistance to water. You should choose with regards to the temperature of the material to which you intend to apply. Some surfaces, like plastic, tend to heat up and expand faster than others. If it is too hot, you will need something more elastic, like silicone-based sealants.

It is important to note that elasticity and elongation are mostly valid in liquid sealant products. This is because; the more fluid sealants are more adaptable to changes. Tape sealants, on the other hand, are mostly inelastic. However, if this is your preference, you should make sure that it is hard to break and water-resistant.

  • Water resistance

This is what most people tend to focus on when choosing a sealant and not unless you enjoy the cool rain drenching both you and your valuables, you should consider this a priority. Well, most manufacturers know this as well, which is why even the basic sealant is made reasonably waterproof. However, in reality, there are those like silicone sealants, which are better at repelling the water than others. You should have this in mind when selecting from your pick.

  • UV stabilization

The sun is one of the most degrading elements on our roofs. It radiates its heat through transparent UV (ultraviolet) beams which cause all sorts of compound responses from substrate materials. With that in mind, it’s important that you have a roof sealant that is UV stabilized and reflects the most sunlight. You can get this quality in brightly colored sealants, but for an overall better experience, the sealant you choose should have that ‘’UV stable ‘tag on their label.

  • Tear resistance

Another aspect of durability is tear-resistance. Here, if the surface forms tears easily, its protective layer creates a point of weakness, making it useless in protecting your roof. Safe to say, you will want the most tear resistance sealant.

  • Rigidity

Rigidity is also important when it comes to durability. You see rigidity in sealants work by adding extra fibers in the formula which in turn adds the overall tolerance to pressure. Highly rigid sealants will do well in areas where there is more foot traffic. Or where it is more exposed to forces from the elements.

Ease of application; which is the most effortless?

When it comes to ease of application, it all falls down to the means of application. How long the sealant would take to dry, as well as how many levels of coating they would need to work best. In this case, silicone comes top as the easiest to apply. Not only does it dry quickly but is also only needs one coat to function well. Overall, silicon is the easiest to apply. When it comes to urethane and acrylic products most, require both a primer coat and other additional coats in order to achieve full capacity.

What color of the sealant should I choose?

Sealants come in different colors. The most common are clear and white. You can choose as per whichever suits your preference and blends well with your particular roof situation. Also noteworthy is that bright colors tend to reflect more sunlight, which is a good thing because they help prevent degradation from the sun’s heat. However, much as white sealants are bright in nature, they are prone to getting dirt more often.

How often should I apply my roof sealant?

Well, this is mostly dependent on what kind of situations you expose your roof to and the climatic conditions of the area you tend to frequent most. Ideally, you might need to apply every 6 months to a year. Best practice would be to inspect your seams after every six months. If you keep your roofs under additional cover, sealing it annually would be sufficient enough.

How do I apply my roof coating?

Applying a roof coating is much easier than you may think. When it comes to any rubber roof or liquid rubber application, preparation is key. That said, you should first ensure that your surface is cleaned before any preparation. For this reason, some sealants come with specialized roof cleaners for this purpose. You can also apply some form of denatured alcohol using a soft cloth for an overall better result. You should also make sure to remove the old sealant that may have been applied initially.

Now, when it comes to the application itself, the ideal weapon of choice would be a caulking gun. Here you’d run a bead of caulk all over the particular part of the roof that needs repairing. That’s basically it. If you need it to repair a crack, you should start by using a lesser amount of sealant, and then apply more if need be.

What number of coats should I apply?

This number of coats you need purely depends on the type of rod sealant that you need. If you are using urethane or acrylic sealants, you will need to use the primer as well as a couple of sealant coats. If it’s silicone-based, in most cases, you’ll only need one coat, without a primer. That said, when using acrylic or urethane coatings, it is best to apply thinner coats as opposed to one thick coat. In this way, your roof will be much more secure in general.

Conclusion

Overall, roof sealants are a wise addition to any roof, whether damaged or not. They increase the resilience of your roof to the elements and will help save a ton of energy and money on roof repairs. That said, you should keep in mind your own particular goal or objective that you intend to achieve and budget at hand before selecting your particular sealant.

If all you need is some minor touchups on roof penetrations or leaks, caulking would be the most common solution. On the other hand, if you want to make an overall barrier of protection against weathering damage or UV damage to your roof, you might need to consider coating or a roof sealant that matches your roof’s rood type. We hope our top selection plus buyers guide will bring you a step closer to keeping a stronger roof above you and your family’s head.

Adrian Dimakis

Written by Adrian Dimakis

Adrian Dimakis loves writing about everything tech, gadgets, travel and leisure as a full time editor at LearningRegistry. Adrian graduated from UCLA with a degree in journalism and marketing, and his work has appeared in publications including USAToday and The Boston Globe. When he's not testing gadgets and accessories, checking different online services, you can find him planning his next trip on a big paper world atlas with lots of pins. Adrian is also an avid consumer with an oddly deep love for finding amazing deals on amazing products.

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