Does Flex Seal Work? An In-Depth Explanation

Flex Seal is a liquid rubberized coating that can be sprayed onto surfaces to create a waterproof barrier.

It can be used on everything from roofs and gutters to boats and RVs. And because it’s weatherproof, it can even be used outdoors.

Flex Seal does an excellent job of sealing leaks and cracks. However, it’s important to note that Flex Seal is not a permanent solution.

It will eventually degrade over time and will need to be reapplied. Nevertheless, it’s a great temporary fix for leaks and cracks.

flex seal spraying on aluminum roof

Over the years, Flex Seal has become increasingly popular. This is likely due to its low cost, easy application, and effective results.

DIYers and professionals alike have turned to Flex Seal for its waterproofing properties.

How Does It Work?

Flex Seal is a liquid rubber sealant that can be sprayed on virtually any surface to create a waterproof, airtight seal.

The key ingredient in Flex Seal is a synthetic rubber compound known as polyurethane.

This compound is suspended in a proprietary liquid solution, which allows it to be sprayed evenly onto surfaces.

Once applied, the polyurethane quickly cures into a flexible, rubbery coating that bonds tightly to the surface. In addition to its waterproofing properties, Flex Seal also acts as an insulator and sound dampener.

Because it is so versatile, Flex Seal is an excellent choice for sealing leaks in a wide range of household items, such as pipes, gutters, windows, doors, and more.

In addition, Flex Seal can be used to repair boats, cars, RVs, and other vehicles. It is also great for craft projects and DIY repairs.

When to Use Flex Seal?

Flex Seal can be used on a variety of surfaces, both indoors and outdoors. Here are some common uses for Flex Seal:

Sealing Leaks

Flex Seal is an ideal solution for sealing leaks in both commercial and residential settings. In addition, the product can be used to seal boats, RVs, and other vehicles.

Whether you’re trying to keep your home dry or your boat afloat, Flex Seal is an excellent choice for leak prevention.

Coating RV Roofs

It’s perfect for coating RV roofs. Flex Seal can be applied to EPDM, TPO, fiberglass, plywood, and metal roofs.

The product will create a durable, waterproof barrier that will protect your RV from leaks, sun damage, and more.

If you’ve ever dealt with a leaking roof for your RV, you know how frustrating it can be. Not only is the leak itself a nuisance, but it can also lead to other problems, such as water damage and mold growth.

While it’s true that getting to the root cause of the problem is the best way to fix a leaking roof, sometimes, you need to come up with a temporary solution until you can get the repairs done. That’s where Flex Seal comes in.

Coating Boat Hulls

Flex Seal can also be used to coat boat hulls. It will create a watertight seal that will keep your boat afloat and protected from the elements.

a man painting the boat hull


Aside from waterproofing, it can be sprayed onto various surfaces to insulate them and protect them from moisture, melting ice, and extreme temperatures.

For example, it can be sprayed on walls in order to keep out moisture or sprayed on boats to protect them from sun damage.

Noise Dampening

When it comes to dampening noise, Flex Seal is an effective solution. It’s an excellent sound dampener and can be applied to the floor, doors, and even the walls of your vehicle.

The thick, sticky adhesive helps to create a seal that blocks out sound. In addition, the material is flexible, so it can be easily applied to a variety of surfaces.

As a result, Flex Seal is an ideal solution for reducing noise in your home or office.

Sealing Cracks in Concrete

Flex Seal can also be used to patch holes and cracks. The material easily conforms to the shape of the opening, creating a watertight seal that prevents leaks.

In addition, Flex Seal is tough and durable, so it can withstand wear and tear. As a result, it is an ideal solution for repairing holes and cracks in walls, ceilings, and floors.

asphalt floor crack repair

Types of Flex Seals

Flex Seal comes in a variety of formulations, each of which is designed for specific applications.

For example, Flex Seal Liquid is a great choice for sealing leaks and cracks. Flex Seal Brite is perfect for coating RV roofs and other vehicles. And Flex Seal Clear is ideal for creating an invisible seal on glass, metal, and other surfaces.

How to Apply Flex Seal Properly

The first step is to clean the surface that you will be applying Flex Seal. This will ensure that the product adheres properly and does not cause any damage.

Next, you need to remove any loose debris or dirt from the area. Once the surface is clean, you can apply Flex Seal directly from the can.

For best results, apply a thin layer and allow it to dry completely before adding additional coats.

You can also use a brush or roller to apply Flex Seal to larger areas. Once the Flex Seal is dry, it will create an airtight, watertight seal that is incredibly durable.

It can withstand extreme temperatures and weather conditions, making it ideal for use both indoors and out. Flex Seal can be applied to a wide range of materials, including metal, glass, ceramics, wood, and plastic.

It is also safe for use on food containers, making it perfect for sealing leaks in Tupperware and other storage containers.

How Long Does Flex Seal Last?

Flex Seal can last for many years if it is properly applied and maintained. However, it is important to note that Flex Seal is not permanent and will eventually need to be reapplied.

The lifespan of Flex Seal will depend on a number of factors, including the climate, the surface it is applied to, and how often it is exposed to sunlight and moisture. With proper care, Flex Seal can provide an effective waterproof barrier for many years.

Final Thoughts

Flex Seal is a versatile product that can be used for a variety of purposes, from sealing leaks to coating RV roofs.

It bonds well to most surfaces and creates a durable, waterproof seal that will protect your surface from damage. In addition, the material is flexible, so it can be easily applied to a variety of surfaces.

As a result, Flex Seal is an ideal solution for a variety of needs. Whether you’re trying to keep your home dry or your boat afloat, Flex Seal is an excellent choice for leak prevention.