7 Best Sealant for Metal Roof in 2024

What’s the best sealant for metal roof? If you intend to achieve a perfect finish on your metallic roofing task, then you’ll need to choose the best sealant for a metal roof. Best Sealant for Metal Roof

Alternatively, your metal roof may be leaking, and this may worry you about how to go about it. Often, people find themselves entangled among conflicting options available in the market and, at times, end up choosing the wrong sealant.

Indeed, it becomes very complicated and expensive if you think of replacing the entire leaking roof. So, let’s get started. See Also: best paint sprayer for interior walls.

Top 7 Best Sealant for Metal Roof in in 2024

1. Liquid Rubber Color Waterproof Sealant – #1 Pick

Liquid waterproof sealant is our top-ranking product that features a highly flexible tough membrane (on application), which prevents your metallic roof from Ultraviolet radiation. The sealant works by creating a lightweight, rigid layer that sticks nicely on the roof and prevents direct action of any harsh weather conditions from damaging the roof.

Best Sealant for Metal Roof Check Price on Amazon

Liquid rubber is manufactured, especially without solvents or VOC additives, thus making it nature friendly- it can be used in any type of roofing without defacing. Also, the water-based sealant has quick-acting agents that make it dry fast (cures within 24-48 hours) to form a smooth surface finish.

This product is safe for both humans and pets – it doesn’t produce poisonous gases or odor. The product is refined with a natural fragrance that won’t irritate your nasal cavity during application.

Liquid rubber has a super active agent that enables it to penetrate deep into any tiny holes or cracks on the roof instantly. More so, the sealant stretches uniformly, leaving a classic air-free cover. The beautiful liquid is more comfortable to apply using a brush, quality paint sprayer or roller and has a shiny reflective surface that keeps off excess sun radiations.

Liquid sealant has excellent chemical resistant properties that enable is to keep off any chemical reaction on the roof surface such as acid rain or polluted air contact. Besides, the sealant comes in various colors (beige, white, grey, brown) that leave a beautiful, impressive seal after application.

The product is easier to clean and remove – it won’t stain your clothes on contact. Furthermore, the sealant doesn’t harden on the first use (you can close the can and store it for future use without sacrificing the quality). See Also: best antifouling paint for fiberglass.

Apart from metal roofs, this sealant can also be used on planter boxes, wooden surfaces, ponds, concretes, or basements to serve the same purpose. The product is packed in an extra-large container that will cover a large surface or several coats.

When applying, avoid any wetness, dirt, or oily surface. For best performance, consider using 2-3 coats (apply each coat after every four days). It’s waterproof and prevents UV radiation and comes in a large container package with varying sizes.

Importantly, Liquid rubber is best for both small scale and large-scale project. It is financially manageable product. Indeed, the sealant comes in a classic container that has a comfortable handle, which allows easier transportation. No solvents or VOC additives, easier to apply – has fine molecules and great flowability.


  • Best for small and large scale projects
  • Highly portable and comfortable– has a nice handle grip
  • Has no poisonous emissions or odor
  • Easier to clean – don’t stain clothes on contact
  • Excellent chemical resistant properties – not affected by acid rain
  • Has a tough flexible membrane
  • Multiple colors and variety of use
  • Deep penetration and beautiful surface finish


  • Needs 2 or 3 coats for best performance

2. Flex Seal Liquid Rubber in a Can -#2 Pick

Flex seal is a liquid rubber based sealant that is made of strong, well-refined liquid component meant to improve its stick ability upon application. The sealant is mixed with bio-active ingredients that improves its penetration action and stickiness strength.

Flex Seal Liquid Rubber in a Can Check Price on Amazon

Actually, the sealant has flexible rubberized membrane that claims to deliver top performance by eliminating UV rays and growth of microbial on your metal roof. In fact, the product forms a uniform waterproof coat that keeps the roof surface at optimal humid temperature on application.

Indeed, Flex seal is manufactured in a top refined state that allows a more straightforward application either by brush, dip, roll, or pour on. Moreover, this sealant cures nicely, leaving a perfectly smooth surface. The tough coating created by Flex seal will not only prevent your metal roof against corrosion and rust but will also keep off chemical reactions and mildew.

More so, this sealant is non-flammable, non-hazardous, and will not emit toxic fumes that may irritate your respiratory system during application. Flex seal guarantees you a 100% plant and animal safety upon us – it’s environmentally friendly.

Flex seal requires no additive such as primers during application (direct application) – all you need to do is to shake and start applying. The sealant forms a thick and sturdy coat at the metallic roof joints and gutters, thus preventing any water from penetrating. See Also: best ladder for painting 2 story house.

Importantly, this sealant is packed in a relatively large container (3.79 liters), which covers 18.75 square feet area nicely. Typically, one layer seal works beautifully. However, for long life and optimal performance, you can add 2 or 3 layers after 48 hours intermittently.

Remembers, you can use Flex seal in other places such as basement, ponds, watersports, car bodies, boats and gutters without any problems. Its waterproof and stain free, easier to clean and remove, deep penetration – has bio-active agent and 100% safe for both animals and plants.


  • Strong stickiness and scratch resistance
  • Flexible rubberized membrane – prevents UV rays
  • Non-flammable and non-hazardous
  • Don’t irritate nasal cavity- no toxic fumes
  • Relative large can – 3.79 liters
  • Top refined sealant and easier to apply – brush or roll
  • Direct application allowed and long service life
  • Prevents corrosion and rust
  • Keeps off mildew and reactive chemicals
  • Budget friendly


  • Irritates the eyes on contact
  • Extra cans for large projects

3. Sashco Through The Roof Sealant -#3 Pick

Sashco is a special sealant made with super freeze thaw stability that makes it perform excellently in extreme low temperatures (-18 degree Fahrenheit) without failure. In fact, the product can be used in a wide range of temperature- up to 120 F- without sacrificing the quality of the metal roof final finish.

Sashco Through The Roof Sealant Check Price on Amazon

Actually, Sashco is one of the only sealants that works directly on the wet surface (no drying or dirt removal needed). Normally, the product forms a watertight seal that blocks the leaking water roofs instantly on application without dilution.

This sealant is refined with an elastic low-VOC grade formula that prevents thawing or freezing during the winter/cold season. Moreover, Sashco forms a tough coat (20 times stronger than the concrete roof) that not only protects your metal roof against UV rays but will also keep off wetness and dirt deposits.

The USA made sealant is highly elastic and durable. It is packed in a 310 ml cartridge (12 packages) that is nicely designed to allow point application during use. Furthermore, the product quantity is sufficient to cover a large area. More so, you can easily press the can when applying – the molten liquid leaves at 10.5 Oz that is flexible enough to bend into the metal roof design without any hassle.

Sashco sticks, instantly leaving an excellent surface finish. You can even mold/ press it to the shape you want during the application. Indeed, this sealant won’t irritate your skin on contact or stain your clothes – it is easier to clean. Easy gun application – allows point application.

However, this sealant is flammable and the vapor formed (after heating) may be poisonous if inhaled. Notably, you can use Sashco on plastic, metal roof, wood or concrete effective. Works nicely even in wet surfaces, forms tough scratch resistant coat, xtreme temperature action – down to -18 F.


  • Very tough -20 times stronger than cemented roof
  • Large quantity -310ml can – 12 cartridge package
  • Water-tight instant seal
  • Blocks leaking metal roof instantly
  • Elastic low-VOC grade formula – no freezing
  • Prevent UV and easier to bend can
  • Wide temperature range- stay tough up to 120 F
  • Highly elastic and durable
  • Easier to apply and stick strongly
  • Works for metal, wood, plastic or concrete
  • Standard 10.5 Oz cartridge


  • Flammable
  • Vapor is poisonous if inhaled

4. Liquid Rubber Seam Leak Tape

Liquid rubber seam tape is a classic designed metal roof sealant that features a strong adhesive compound, which sticks strongly without release. The product is manufactured using a highly flexible material that allows it to curve and conform nicely with the shape of the surface being sealed.

Liquid Rubber Seam Leak Tape Check Price on Amazon

The Product is fully waterproof and claims to deliver excellent contact retention without release for long. Moreover, Liquid rubber tape is made in large size (2” x 5 feet) that covers a relatively long length when sealing. Indeed, this product is also packed in different sizes according to your order.

The sealant tape is toughened with extra thick material that is scratch resistance. Moreover, you can use the product in very extreme temperatures (-70 F) without losing the quality of the contact since the product material contain the anti-thaw agent. See Also: how to stain a deck for the first time.

The simple to peel lining of Liquid rubber tape conforms nicely with your metal roof profile and aligns perfectly along the joint without leaving any opening. More so, you can stick and paint the surface of the tape without affecting the quality of adhesive contact.

Not to forget, this Liquid rubber tape is integrated with a compound that not only prevents the roof against the UV rays but also keeps off mildew and dirt deposit. Further, the tape is specially made to prevent thermal cycling, salt, and chemical reactions when used in a harsh environment.

The sturdy rigid cover of this tape is made of heavy-duty material that is non-elastic. It is furnished with a complex compound that keeps off oil or flaking, thus remaining ever-impressive where it’s used. Its waterproof and scratch-resistant, with long tape length- 2″ x 5 feet roll and various package options.

Remember, this sealant tape can be trimmed easily. You can also use it in a wide range surfaces such as metal roof, joints, concrete, wood etc. Furthermore, the product is budget friendly and highly portable. Its highly flexible material and easier to use/seal, has a strong adhesive and durable – long service life.


  • Conforms to any shape and size
  • Works in extreme temperature conditions – -70 F
  • Suitable for joints and bent seal
  • Tough and rigid outer cover
  • Free from oil dirt or flaking
  • Prevent UV rays penetrations
  • Resist thermal cycling, salts and chemical reactions
  • Simple to peel stick and paint
  • Made from heavy-duty material


  • Requires a clean surface

5. Deck Flex All-Purpose Clear Protective Sealer

Deck flex is a water-based sealant that is manufactured using bio-active agent to improve its stickiness during applications. The product features a highly refined liquid mixture that has super ablative flow and roll ability, which makes is easier to apply.

Deck Flex All-Purpose Clear Protective Sealer Check Price on Amazon

The sealant is dedicated to deliver excellent seal since it forms a tough scratch resistant coat upon application. Moreover, Deck flex is industrial strengthened to fit perfectly for use in both residential and commercial metal roof sealing project.

The USA made sealant is 100% waterproof (no leaking or moist walls) and acts instantly on application. Indeed, the sealant has a long service life (durable). You can trust Deck flax with beauty since the product endeavors to deliver a smooth and elegant final surface finish that makes the metal roof very attractive.

The versatile product is packed in and an extra-large container that will seal a common area of 400 square feet per gallon. Moreover, the sealant dedicates its water-based formula to deliver quicker drying action (1 hour) without sacrificing its top quality. However, you will need to apply a 2-3 coat every three days to achieve excellent roof protection.

Deck flex can be applied by either brush, roller, or airless sprayers for effective contact. This product is safe for both humans and pets. Deck flex won’t stain your clothes or irritate your skin on contact. Its made in the USA and strong adhesive bond and comes with a beautiful and smooth surface finish.

It can actually be cleaned and removed easily when necessary without hassle. Remember, you will need to purchase sealant-applying accessories since they not included in this product. Has a strong bio-active agent and eco-friendly, extra-large container and easier to apply, long service life and waterproof.


  • Versatile and industrial strengthened
  • Wide are application – 400 sq. ft per 1 gallon
  • Fast drying – 1 hour
  • Best for commercial and residential use
  • Effective for metal, wood, concrete and shingle surfaces
  • Quick acting – water based formula
  • Don’t stain your clothes or irritate skin
  • Easier to clean and remove


  • Slightly longer drying time for second coat– 72 hours
  • Slightly heavy
  • Limited colors

6. HEAT-BLOCK – 5 Gallon Metal Roof Sealant

Heat block is a tough rubberized sealant that is thermal refined to improve its elasticity needed to generate a uniform seal cover. Actually, the product features a tough heat block reflective properties that gives it a super quality performance and long service life.

HEAT-BLOCK - 5 Gallon Metal Roof Sealant Check Price on Amazon

The sealant has 90% solar relativity (energy saving) that not only sieve the ultra violet radiations but also maintains the roof at optimal humid condition upon application. Moreover, the Heat block is 100% waterproof and weatherproof – this means that it can be used in any environment or climate (cold or hot) without sacrificing its top performance.

The eco-friendly sealant has no solvent additives, and thus it’s safe for both humans and pets. The product won’t stain your clothes or irritates your skin upon contact. You can clean and remove it quickly, where the need is, without any challenge. See Also: best stain for swing set.

The Heat block comes in a large container that will serve a wide area during use. Moreover, the sealant is packed in various sizes, thus making it suitable for both residential and commercial use projects. You can trust top quality delivered by Heat block since it claims to leave a tough scratch resistant surface finish upon application.

The LEED-certified sealant is more comfortable to apply – all you need is to kick lid open, get a brush, roller or sprayer and begin the direct application. Importantly, Heat block is economical for a large project and can be used on various surfaces such as metal roofs, concrete, wood, basement, etc.

It has Rubberizes compound to improve elasticity, extra-large containers and different size packaging, heat block reflective properties, and leed quality application certified. Its 100% waterproof and weatherproof, eco-friendly – contains no solvents and highly portable and comfortable handle grip.


  • Multiple use – Metal roof, plastic, concrete, wooden etc.
  • 90% solar relativity – energy saving
  • Tough scratch resistant coat
  • Easier to apply and remove
  • Don’t irritate your skin or stain clothes on contact
  • Best for residential and commercial use
  • Wide coverage and budget friendly


  • Require 2-3 coats for best performance
  • Slightly Expensive
  • Heavy for youth

7. GacoRoof GR1600-1 White Silicone Roof Sealant

GacoRoof is a silicone-based sealant, which is manufactured with ablative touch action formula for easier application and to improve stickiness bonds. The sealant has a powerful eco-agent that activates the silicone component to form a seamless tough membrane that is scratch resistant upon application.

GacoRoof GR1600-1 White Silicone Roof Sealant Check Price on Amazon

Actually, GacoRoof is refined with user in mind to attain fine molecules that have nice flow and roll ability, which makes it easier to apply using a brush or a roller. Moreover, the product forms a tough seal that not only protect the metal roof against UV rays, but also act as a water proof membrane (prevents any water leakage).

This product doesn’t stain your clothes or irritate the skin on contact. You can trust the environment-friendly sealant with a 100% safety for both humans and pets. However, GacoRoof may irritate the eyes on touch or cause stomach upset when swallowed – it should be kept away from kids.

Further, this sealant is packed in a relatively large container that will cover a wider area. Not forgetting, GacoRoof comes in an excellent handle grip that makes it very comfortable when transporting.

The product doesn’t produce poisonous fumes that may affect your respiratory system. Neither is it flammable. You will like the beautiful smooth final finish that this sealant claims to deliver- it is white.

Notably, GacoRoof is budget-friendly and has multiple applications. It offers instant action and fast-drying, creates a seamless, tough membrane, highly refined liquid mixture, and more comfortable to apply, beautiful white color, and classic final finish.

Also, the sealant offers UV rays protection and Waterproof, scratch resistant and prevents rusting & corrosion, great ablative formula – high flow and roll ability, and its safe for both Human and pets. See Also: best paint stripper for metal.


  • Produce no poisonous fumes or odor during application
  • Easier to clean and remove where necessary
  • Don’t stain clothes or irritate skin on contact
  • Relatively large container and wide seal area
  • Highly portable and comfortable hand grip
  • Silicone based sealant compound
  • Permanent protection seal and budget friendly


  • Limited colors
  • No Application accessories
  • May require 2 or 3 coatings


When you intend to achieve a top quality roof protection, it would be wise to choose the best sealant for metal roof. This may not be easy as per say.

You will need to consider the quantity in the container, the stickiness action power, action time, durability, number of coats needed as well as the means of applications.

As if that is not enough, check the product’s safety and precautions needed during application. Otherwise, you may end failing to achieve the objective.

Similar Posts