The Best Gutter Sealants to Prevent Leaks and Damage, Tested

Hello, my friend, hello again; today we come together to talk about The Best Gutter Sealants to Prevent Leaks and Damage, Tested and hope the blog can help you.

Don’t let leaking gutters lead to water damage in your home. Get the repair right the first time with these effective solutions.

The main purpose of guttering is to channel rainwater away from the home and prevent it from damaging the foundation or seeping into the basement. During installation, rain gutter end caps and seams are coated with a flexible sealant designed to withstand hot and cold weather and moderate impacts. However, the gutters themselves are subject to all kinds of harsh conditions, which, combined with aging, could inevitably cause them to leak.

Several effective approaches to fixing rain gutter leaks and plenty of different gutter sealants are available to consumers. However, gutter styles and materials vary considerably. What works well on vinyl, for example, may not be as effective on galvanized steel, aluminum, or copper. Plus, different kinds of damage require different repair techniques. One product may work better for pinholes or cracks, while another product may be required for a separated end cap.

As a result, we decided to test a variety of gutter installation and repair products, including exterior caulks, tapes, and roof sealants. They differ significantly in application methods and curing times, but each one is capable of creating a watertight seal on vinyl, PVC, and metal gutters. Whether your project involves new gutter installation or repairs and maintenance of old rain gutters, one of the following best gutter sealants available today will be able to handle the task.

1. BEST OVERALL: Geocel 2320 Tripolymer Gutter and Narrow Seam Sealant
2. BEST BANG FOR THE BUCK: Amerimax SeamerMate Gutter Sealant
3. BEST FOR LEAKS: Liquid Rubber Waterproof Sealant
4. BEST QUICK FIX: Gorilla Waterproof Patch & Seal Tape
5. BEST MULTISURFACE: OSI Quad Max Clear Paintable Sealant
6. BEST FOR METAL GUTTERS: GE Metal Silicone 2 Sealant
7. BEST SPRAY: Rust-Oleum LeakSeal Spray
8. BEST TAPE: XFasten Super Waterproof Aluminum Butyl Tape
9. ALSO CONSIDER: Flex Seal Spray-On Liquid Rubber Sealant

How We Tested the Best Gutter Sealants

We simulated gutter installation and gutter leak repairs in our tests and evaluated how each product performed on aluminum and PVC gutters. Using salvaged sections of aluminum and PVC gutters, we first drilled a series of ⅛-inch and ¼-inch holes in the gutter bottoms and applied the sealant product to repair the holes. Then, we used each product to install gutter end caps on both gutter types.

Throughout testing, we made sure to strictly follow the manufacturer’s instructions for each sealant. During the application process, we noted both whether the product was clean or messy to use and how easy or difficult it was to clean up afterward. We also noted the number of applications required, the cure time for each application, the total cure time, and overall durability. After we completed all applications and installations, we filled the gutters with water, observed the water level for 12 hours, and noted any leaks. Finally, we scored each gutter sealant on a scale of 1 to 5 for ease of application, ease of cleanup, quick results, and durability.

Our Top Picks

Our top picks feature a selection of the best gutter sealants on the market. We took into account each product’s effectiveness, value, and environmental impact. While each gutter sealant is a quality product, read on to discover which one may best suit your particular needs.

Best Overall

Geocel 2320 Tripolymer Gutter and Narrow Seam Sealant

See It

Our Ratings: Application 4/5; Cleanup 4/5: Cure Time 3/5; Durability 5/5

Product Specs

• Application: Caulking gun
• Gutter material: All
• Dry time: 5 days

Pros

• Adheres to all types of rain gutters, even when wet or oily
• Flows deep into gaps and seams
• Works at any temperature and in all weather conditions
• Seals narrow seams, gaps, and holes up to ¼ inch by ¼ inch
• Cures to a tough, rubberlike finish

Cons

• Emits a strong chemical odor while curing
• Full cure takes up to 5 days

Building professionals use Geocel 2320 tripolymer sealant because it’s durable and takes the guesswork out of gutter installation and repair projects. It adheres to all types of material, works in any weather, and fills gaps up to ¼ inch in diameter. The self-leveling formula flows deep into the gaps and cures to form a tough yet flexible bond. Each 10-ounce tube contains enough product to extrude a ¼-inch bead of sealant up to 28 feet, using a standard caulking gun. Our tests proved the efficacy of the Geocel 2320 sealant. After loading it in the caulking gun, we squeezed a few small beads of the sealant into the holes we had drilled in the bottom of the gutter, then installed two end caps. This product adhered to anything it contacted, including concrete and wood as well as the gutter materials. It was easy to control the pressure and prevent messes via the dripless feature on the caulking gun. Even though our initial finish was not perfect, the self-leveling texture allowed the ridges and bumps to settle into a fairly smooth finish. The only downside to this product was the cure time. Although a surface skin began to form within an hour, it was extremely pliable for 24 hours. However, after the 5-day cure time, the sealant was very sturdy, puncture-resistant, and fully waterproof.

Get the Geocel gutter sealant at Amazon.

Best Bang For The Buck

Amerimax SeamerMate Gutter Sealant

See It

Our Ratings: Application 4/5; Cleanup 4/5; Cure Time 3/5; Durability 5/5

Product Specs

• Application: Caulking gun
• Gutter material: Metal
• Dry time: 5 days

Pros

• Semi self-leveling sealant makes it easy for DIYers to achieve professional results
• Ultraviolet (UV)-, temperature-, and weather-resistant sealant for all metal rain gutters
• Quality gutter sealant at an affordable price

Cons

• Full cure takes up to 5 days
• Cannot reseal tube to store unused product for an extended period

The Amerimax SeamerMate gutter sealant is a high-quality tripolymer product for metal gutters. Be aware that it is designed to bond metal to metal and may damage other gutter materials. Applied with a caulking gun, the self-leveling formula fills gaps and holes up to ¼ inch and leaves a smooth, tough finish. This sealant is designed for secure gutter installation and repairs that can withstand harsh weather for decades. One of the most affordable gutter sealants we tested, Amerimax SeamerMate was easy to apply, easy to clean up, and formed an incredibly strong bond. Our drip-free caulking gun helped prevent messes.

The product’s self-leveling consistency delivered professional-looking results, and it was paintable the day after application. Although we preferred the final results of the Amerimax SeamerMate over most of the other products, the slow cure time of up to 5 days might be problematic for some users. Also, for a single small repair, the full 10-ounce tube could be excessive, and there is no way to reseal it for later use once you’ve opened it. Still, this sealant is a great product at a great price, best for midsize and larger repairs.

Get the Amerimax gutter sealant at The Home Depot or Ace Hardware.

Best For Leaks

Liquid Rubber Waterproof Sealant – Multi-Surface Leak

See It

Our Ratings: Application 4/5; Cleanup 3/5; Cure Time 4/5; Durability 4/5

Product Specs

• Application: Brush, roller, or piston sprayer
• Gutter material: All
• Dry time: 24 to 48 hours

Pros

• Easily bridges seams, gaps, and small holes over a broad area
• Excellent adhesion and flexibility for flat or shaped vertical or horizontal surfaces
• Remains flexible and durable and will not degrade from sun exposure
• Contains no volatile organic compounds (VOCs) or solvents and emits no harmful odors

Cons

• Relatively slow drying time
• Can require more than 1 coat

While a number of paintable, rubberized gutter sealants on the market are very effective, many are unfortunately solvent-based. Water-based Liquid Rubber sealant has virtually no odor yet all the benefits of its more toxic competitors. You can apply Liquid Rubber with a roller or even a piston sprayer—although the latter requires professional-grade equipment. This product adheres well to both vertical and horizontal surfaces, and the ability to perform without splitting or cracking means it will flex as much as necessary without compromising adhesion. Liquid Rubber is UV-stable, so the sun’s harmful rays won’t damage it.

Depending on the size of the repair, it may need two coats, and a slow drying time means it can take several days to fully complete the repair. In our tests, the first coat felt dry after 12 hours, but we waited the full 24 hours before applying another coat. In all, we applied three coats over the ⅛-inch and ¼-inch holes in the bottoms of our gutters, but two coats would have been adequate. We filled the gutter with water 2 days after the last application, and it held fast. You can paint over this sealant once it’s fully dry.

Get the Liquid Rubber gutter sealant at Amazon or Lowe’s.

Best Value

Gorilla Waterproof Patch & Seal Tape

See It

Our Ratings: Application 3/5; Cleanup 5/5; Cure Time 5/5; Durability 4/5

Product Specs

• Application: By hand
• Gutter material: All
• Dry time: Instant

Pros

• Easy to cut to shape, peel the backing, and cover the seam for an almost instant repair
• Withstands freezing, high temperatures, UV light, and abrasion
• Adheres to prepared surfaces underwater if the surface is properly prepared
• Multipurpose; also works for a variety of wet and dry applications

Cons

• Nearly impossible to reposition once the adhesive contacts the repair surface
• Difficult to remove the tape backing and cut to shape in cold weather

Gorilla waterproof tape provides a durable repair virtually immediately. It is 4 inches wide—a good size for substantial cracks or splits—and is one of the best ways to seal gutter seams. The adhesive grip is very effective on all gutter materials. This product is UV-resistant and can withstand temperatures as low as -70 degrees Fahrenheit up to 200 degrees Fahrenheit. Each roll is 10 feet long, and it will store almost indefinitely in an airtight bag at room temperature.

Although the manufacturer states that you can apply Gorilla tape to wet surfaces, our tests revealed that only dry surfaces work well. The surface also needs to be sound: The tape will lift if the surface is dusty, flaking, or slimy. We had to cut the tape to fit with the backing still in place; otherwise, the tape stuck to the knife or scissors and was very difficult to remove. It’s also important to use caution while positioning the tape. Once we placed the tape, it was nearly impossible to remove.

One downside is that the Gorilla tape didn’t blend well with the gutter surface. The thick profile of the tape stood out, as did the pure white color against the patina of our 50-year-old gutters. Additionally, this product is not paintable and so is best used on the inside of the gutter, if possible, to hide the repair.

Get the Gorilla gutter sealant at Amazon, The Home Depot, or Walmart.

Best Multi-surface

OSI Quad Max Clear Paintable Sealant

See It

Our Ratings: Application 4/5; Cleanup 4/5; Cure Time 4/5; Durability 5/5

Product Specs

• Application: Caulking gun
• Gutter material: All
• Dry time: 24 to 72 hours

Pros

• Fast acting; paintable in 1 hour and full cure in as little as 24 hours
• Versatile product for gutter installation and repairs, flashing, windows, doors, siding, and trim
• Adheres to most building materials, including metal, plastic, masonry, and glass
• Enhanced resistance to UV rays, dirt, dust, and extreme temperatures

Cons

• More expensive compared to other several high-quality options
• Sets up faster than competing products, so cleanup must be addressed promptly

Primarily labeled as a window, siding, and door sealant, OSI Quad Max is also highly rated for gutter sealant applications. It has a higher viscosity than other gutter sealants to allow for faster setup and creates a tough watertight bond that stands up to UV rays, dust, dirt, and extreme weather. This product is an excellent choice if you need to keep a project moving quickly, as it is paintable within an hour and cures fully in as little as 24 hours. During our tests, we noted stiffer resistance on the caulking gun while applying OSI Quad Max sealant compared to most of the other gutter-tested products.

This sealant is also less forgiving of sloppy work. Since it isn’t a self-leveling sealant, it didn’t flow downward into the voids quite as thoroughly, and any imperfections in the bead were likely to remain after curing if we didn’t take the time to smooth them out. However, once cured, our end caps and drilled holes stayed watertight.

Get the OSI Quad Max gutter sealant at Lowe’s or The Home Depot.

Best for Metal Gutters

GE Metal Silicone 2 Sealant

See It

Our Ratings: Application 4/5; Cleanup 4/5; Cure Time 4/5; Durability 4/5

Product Specs

• Application: Caulking gun
• Gutter material: Aluminum, galvanized steel, copper
• Dry time: 24 hours

Pros

• Faster setup than most paste-type sealants; waterproof in 30 minutes
• Low-odor silicone caulk is less irritating during application
• Long-term durability and allows for 25 percent joint movement
• Resists mold and mildew growth for 10 years

Cons

• Cures to a softer finish and lower adhesion than tripolymer-type gutter sealants

While general-purpose products are often capable, specialist alternatives invariably provide a better solution. This GE sealant, for example, is formulated particularly for metals. It is a silicone-based sealant that we applied with great accuracy and economy using a caulking gun during our tests. It flowed easily into gaps, seams, and cracks, and we found the initial drying time to be very rapid. This product is permanently waterproof in around 30