Flex Seal Liquid




Seals out air, water and moisture and is mildew, chemical and UV resistant. Available in black, white, clear, and grey.

• Concrete and asphalt repair

• Foundation repair

• Prevent basement seepage

• Weatherize and seal out moisture

• Home and roof repair

• RV and motorhome weatherizing and repair

• Pools and pool equipment and much more!

Works on: Concrete, glass, brick, stucco, masonry, wood, copper, plastic, tile, fabrics, wires, vinyl, fibreglass, ceramic, porcelain, metal, aluminum, natural stones, foam, asphalt, EIFS, TPO, PVC, EPDM, CSPE, Hypalon polyurethanes and more.

Flex Seal Liquid
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FLEX SEAL LIQUID® is available in pints, quarts, and gallons.

Colour options include black, white, clear and grey. 

It's liquid rubber, in a can! Unlike traditional paints, Flex Seal Liquid starts out as a thick liquid that can seep into cracks and holes to form a waterproof, weatherproof seal. Easy to use, just brush, roll, dip or pour to stop leaks fast.

*Review count based on 5-star amazon.com reviews, collected between May 2020 and May 2021.

Protective clothing is recommended prior to starting any projects, make sure the surface is clean, dry and free of grease, oil and dirt. You can either brush, roll, dip or pour Flex Seal Liquid directly onto surface.

Increase adhesion by etching surface with sand paper.

Allow each coat to dry completely (24 to 48 hours) before adding additional coats. Flex Seal Liquid fully cures in 48 hours.

Tips for Brushing/Rolling Applications

Brush or roll Flex Seal Liquid using an even sweeping motion. Apply several even coats until the surface has been completely covered and ALL cracks and holes have been filled. Always brush or roll over a larger area than just where the leak occurred.

Tips for Dipping Applications

Dip object into Flex Seal Liquid, making a slight swirling motion. Once you feel the surface has been fully coated, remove and let any excess liquid drip back into the can. Hang or clip object in the same vertical position as it came out of the can and let dry.

Once fully cured, you will have a super strong, no slip, rubberized coating on the surface.

Tips for Pouring Applications

Pour Flex Seal Liquid directly on the surface, allowing gravity to take the liquid into cracks, holes, and/or other hard-to-reach areas.Continue to pour until the surface has been covered and all cracks and/or holes have been filled completely.

When pouring Flex Seal Liquid into an area of depth greater than ¼ inch, allow each ¼ inch layer to cure completely before pouring the next layer. Allow at least 48 hours for liquid to fully cure.

WARNING: Avoid contact with eyes and skin. Gloves and safety glasses are recommended. KEEP OUT OF REACH OF CHILDREN.

How much will one can of it cover?

Coverage will vary depending on the number of coats used and what type of surface you are applying Flex Seal Liquid onto. However, our available sizes typically cover the following area:

1 Large 16oz – up to 18.75 sq. ft.,
1 Jumbo 32oz – up to 37.5 sq. ft.,
1 Giant Gallon – up to 150 sq. ft.

What is the shelf life of FLEX SEAL LIQUID?

Flex Seal Liquid has a shelf life of 24 months when properly stored. If the can remains open for an extended period of time a skin may form on the surface. In order to avoid skinning over, remove the lid, use immediately and always replace the lid after each use. If skinning does occur, remove the top layer and use product.

Will it expand and contract in the summer and winter?

Yes, Flex Seal Liquid stretches, stays flexible, expands and contracts.

Can I use it on the inside of my rainwater barrel?

Yes, Flex Seal Liquid is safe on rain barrels (once fully cured).

How much pressure will it withstand?

The maximum pressure Flex Seal Liquid can withstand will vary based on the surface and the conditions under which it is applied. It’s always best to test a small area first.

What temperatures will it withstand?

Flex Seal Liquid has a wide temperature range from -80 to 350 degrees Fahrenheit. For best results, we recommend applying it to surfaces and substrates in temperatures between 32 and 120 degrees Fahrenheit.

Can I dilute it?

Flex Seal Liquid is ready to use and should be used right out of the can. Do not dilute it with solvents or water.

How do I clean it up?

You can clean up excess or spilled product with a dry cloth or paper towel and mineral spirits (BEFORE the liquid begins to cure). DO NOT USE water or alcohol-based solvents.

Can I apply it on a wet surface or when it’s raining?

It’s always best to apply Flex Seal Liquid on a clean, dry surface free of grease and oil. If applied during heavy rain, some of the product may wash away. Therefore, we recommend applying it 24 hours prior to any heavy rain, hail or snowfall (if possible).

Can I use it to repair a gasoline tank?

We do not recommend using Flex Seal Liquid to seal a gasoline tank or any other flammable liquids.

Can I paint it?

Once fully cured, Flex Seal Liquid can not be painted over with most traditional paints.

Can I use it on underfoot applications?

No, we do not recommend using Flex Seal Liquid on underfoot applications.