10 Best Roof Sealants for Leaks in 2023 – Reviews & Top Picks

Whether you’re eating dinner or relaxing in front of the TV, it’s annoying when water drips on your head. The most common cause of leaks is roof damage, so that means you need a roof sealant. How do you choose what the best product is when there are so many out there? Let us describe some of the most useful roof sealants so you can get that leak sealed ASAP.

A Quick Comparison of Our Favorites in 2023

The 10 Best Roof Sealants for Leaks

1. KST Coating – Best Overall

Once applied and cured, this roof coating is UV resistant and resists mold, mildew, and cracking. The coating contracts and expands with your roof as the summer heats up and the winter cools it down.  KST coating protects your roof from UV damage and water damage with a leak-proof seal. It fills small holes and adheres to most materials, including metal, shingles, asphalt, and other conventional roofing structures. However, these solvent-based paints are extremely strong and require lots of ventilation when working with them.

---

2. Gorilla Waterproof Patch & Seal Tape – Best Value

The Gorilla brand has made its name on its superglue, but the company makes excellent waterproof tapes and patches as well. One 10-foot roll should be plenty enough to repair any small leaks on your roof without shelling out for a bucket of liquid sealant. If you’re especially sensitive to solvent-based odors, this tape spares you the headache. This tape sticks to most roofing materials but is not suitable for patching shingles. It might not adhere to liquid sealant products, either.

---

3. LR Liquid Rubber Waterproof Sealant – Multi-Surface Leak Repair Indoor and Outdoor Coating – Best Multi-Surface Product

LR Liquid Rubber can protect just about anything, or so it claims. This polymer water-based sealant is easy to apply with heavy coats, and it’s so heavy-duty that it can be used to coat the bottom of ponds. Unfortunately, it only comes in black, which doesn’t help reflect UV rays. Unlike other oil-based sealants, LR Liquid Rubber contains no flammable chemicals and is relatively easy to spread. You can use this product to seal small leaks or to cover up more extensive problems.

---

4. Henry HE587372 Roof Coating – Best for Flat Roofs

This roof coating from Henry is highly durable once cured and will reflect over 90% of UV radiation from your roof. Most importantly, the coating is breathable when applied, which means it can contract and expand with your roof structure. This product claims to reduce the temperature of your home by 40°F, which improves your HVAC system’s efficiency. However, the quality isn’t fully there, so you may need to apply multiple coats when using it.

---

5. Liquid Rubber Peel and Stick Seam Tape

Liquid Rubber also offers a robust peel and stick waterproof seam tape to help reinforce any other roofing sealants you apply to your roof. The adhesive backing sticks to metal, shingles, and rubber alike, so it’s relatively versatile. If you have a few areas that are leaking or could use an extra layer of protection, this tape will work well. Unfortunately for inexperienced users, this tape is only useful if you know exactly where your leak is. It also isn’t UV resistant like a lot of other popular options.

---

6. Rubberseal Liquid Rubber Waterproofing and Protective Coating

This product is especially great at securing flat roofs prone to water damage from standing water. Rubberseal forms a protective barrier that’s impervious to standing water, and its high solar reflectivity makes it ideal for the harsh summer sun too. Interestingly, this product is available in a multitude of colors so you can match your roof’s color while protecting it. The main con of this product is that it’s oil-based and difficult to spread evenly. It also has a very strong odor, so be prepared when you crack open the container.

---

7. Loctite PL S30 Black Roof and Flashing Sealant

Roof flashing is a vital part of any roof, providing an extra layer of protection. Damage to roof flashing can cause small or large leaks in your roof, and it’s not always easy to spot. This caulking product helps to reach normally inaccessible areas, like far underneath damaged roof flashing. This sealant restores the barrier between the flashing and the roof and is especially useful for metal roofs. Unfortunately, it also hardens at the tip of the tube. This makes it harder to save for later use, so it isn’t really the best value for your money if you want it to last a long time.

---

8. Flex Seal Spray Rubber Sealant Coating

If you’re averse to painting, Flex Seal offers a super-easy way to apply a no-leak rubber sealant to your roof. Once dried, the rubber coating can be painted any color to match your roof or other flashing. This product is also great at weather sealing windows, skylights, or other fixtures around your house. This may not be as heavy-duty as some other products on this list, but it’s easy, fast, and surprisingly effective. It isn’t UV resistant like other products on our list. Plus, the rubbing coating isn’t as durable. This is a product better for small leaks.

---

9. Sashco Through The Roof Sealant

Catchy name aside, Sashco’s Through The Roof Sealant is powerful enough to work even when applied to standing water, so you don’t have to wait for your roof to dry to fix a leak. The copolymer rubber coating will stick to just about any roof surface, including metal, shingle, asphalt, and concrete. Once dry, this sealant is clear and fully paintable. Because it is solvent-based, this is another sealant that requires plenty of ventilation from harsh fumes.

---

10. Gorilla Waterproof Patch & Seal Spray

If you liked the Gorilla tape above, you’ll probably like their spray sealant too. It’s easy to spray and dries clear, so you can paint it when you’re done. Like other Gorilla products, this adheres to virtually any surface you can name. The resulting barrier is waterproof, clear, and flexible, so it will breathe with the roof. As with other spray sealants, this is only good for small leaks. You definitely can’t cover an entire roof with it. Plus, it isn’t as durable as other products on the list.

Buyer’s Guide: How to Select the Best Roof Sealants for Leaks

Having to seal a roof can be a big job. A lot of homeowners don’t even know where to start. This buyer’s guide will give you a few tips to ensure that you purchase the right products for the job.

Spray and Tape Sealants

If you only have a small leak, you should go with one of the spray or tape options. These usually don’t require too much effort from you. They get the job done but don’t last as long as other types of sealants that you can buy.

Tube Sealants

If you have a leak underneath some damaged flashing, any sealant that comes in a tube with a caulk tip will help you reach the leak’s location more easily. This is perfect for reaching into tight nooks and crannies that you can reach with your fingers or a large paint roller. It is also ideal for smaller jobs.

Solvent-Based Sealants

These types of sealants are designed to be used on large roofs, with multiple application methods and time-tested durability. If you dislike the smell of solvent-based products, consider a spray or tape product. However, that isn’t ideal if you’re working on a big project or an entire roof.

Conclusion

It can be concerning when you have a persistent leak in your house because of roof damage, but there are tons of options for any possible leak. Our choice for the best overall roof sealant comes from the KST coating. However, anyone looking to seal a small leak might turn to the Gorilla Waterproof Patch & Seal Tape. Whether you want to cover a large area because you’re unsure of the leak’s source or just something to cover a known crack, this list has you (and your roof) covered.

---

Featured Image Credit: Giorgio Trovato, Unsplash