Flex Paste® Flood Protection (Cartridge)

Flood Paste in a Cartridge is the primary Flood Protection product and should be used as a base coat for your first layer of protection and in combination with our other Flood Protection products.

• Flood Protection Paste in a Cartridge has a precision nozzle that allows you to target specific areas that need to be sealed.

• Use on all types of openings such as windows, doors, seams, garages, casings, thresholds, conduits, vents and ducts, key holes and more.

• Once waters recede, our Flood Protection Paste can be easily removed.

For complete instructions, visit flexsealproducts.com/flood.

No water penetration through 1/2 inch gaps at depths up to 3 feet, for 14 days. UL Verified. VerifyUL.com. V114667.

We’re proud to say that when used in combination, and as directed, our Flood Protection Products have been independently verified by UL Solutions to hold back 3ft of water for 14 days on gaps up to ½ inch. Tested in laboratory settings.

Patent Pending for Products and Uses.

Bulk Discounts

Orders over $500 - get 5% off

Orders over $2,500 - get 10% off

Orders over $10,000 - get 15% off

Orders over $20,000 - get 20% off

Discount applied at checkout.

Cannot be combined with other offers.

Flood Protection Paste (Cartridge)
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For more information or any questions, call our Customer Service Center at 833-4-A-FLOOD (833-423-5663)

Our Flood Paste in a Cartridge starts out as a thick paste that can be pushed deep into all types of openings and hard-to-reach areas. It dries to a strong, flexible, rubberized barrier. It seals out water, air, and moisture and remains completely flexible. Once floodwaters recede, our Flood Paste can be easily removed.

Flood Paste in a Cartridge is the primary Flood Protection product and should be used as a base coat for your first layer of protection. The cartridge nozzle allows you to target specific areas that need to be sealed. Use on windows, doors, garage doors, and all types of seams, casings, thresholds, conduits, vents and ducts, keyholes, and more.

When applying our Flood Protection Paste in a Cartridge, always to push the Flood Paste into all seams and openings using a gloved finger, Flex Gap filler tool or similar tool. This will help create a watertight seal. A common mistake is not pushing the paste into the opening being sealed. Always be cautious of any sharp objects that may cause injury. For complete instructions go to: flexsealproducts.com/flood.

California Residents: Prop 65 Warning(s)


Depending on temperature, humidity and thickness of application, Flood Paste will dry to the touch in approximately 2 to 6 hours, and fully cure in approximately 24-48 hours.

Allow product to fully cure before floodwaters arrive. To reuse cartridge, leave a small bead of paste at the tip of the nozzle to create a plug. When reusing, remove plug from the nozzle. Always use fresh material to seal an opening.


Flood Protection Cartridge (9oz): A 1/4" inch bead will cover approximately 21 linear feet.

Flood Protection Cartridge (28oz): A 1/4" inch bead will cover approximately 62 linear feet.


Always follow state and local weather advisories and evacuation orders. Depending on age and type of construction, there may be areas that can’t be seen or sealed. Unsealed porous surfaces may seep water during extended underwater exposure. Our Flood Protection Products are NOT intended for flash floods, extreme winds or water pressure, to protect against flying or floating debris, or if there is structural damage to the building.


All of our Flood Protection Products are Patent Pending for both products and uses.

Made in the USA with globally sourced materials.

Color of product is high-visibility yellow.

For more information on UL testing, click here.

For instructions on how to seal doors, windows, electrical outlets and other areas around your home or business, visit: flexsealproducts.com/flood

Read entire label for directions and warnings before use.

• Protective gloves, clothing, andeyewear are recommended.

• Apply to the exterior of the structure.

• Area being sealed must be clean, dry, and free of grease, oil, and dirt.

• Unscrew nozzle, cut the nub on the cartridge, being careful not cut or damage threads.

• Screw nozzle back on cartridge and cut nozzle to the desired thickness of the bead.

• Place the cartridge into a caulking gun.

• Using a smooth motion, apply an even bead directly to the areas being sealed.

• Use your finger or tool to push the bead into the surface being sealed. (Gloves recommended)

• Apply additional coats after 2-6 hours or when dry to the touch.

• Additional coats should overlap and be wider than previous coats.

• Material can be tooled for approximately 10 to 15 minutes before curing begins.

• Allow approximately 24 to 48 hours to fully cure before floodwaters arrive.


Grab a small portion of material from an edge and pull away from the structure. Using a small pair of pliers may be necessary. If any residue is left on the surface, use a stiff nylon brush, paper towel or rag with denatured alcohol to clean the area.

Simply place an order and we can act as an exporter by shipping to your freight forwarder in the contiguous United States.

We will provide the required export documentation, complying with export regulations for your international ocean shipment.

For more details, contact our International Customer Service at +1-833-423-5663 or use the contact form below, and our associates will gladly assist with all export issues.

Customer is responsible for export fees, international freight, customs duties and all other related fees. Customer is solely responsible for product compliance issues in the country of destination. All international orders are final and cannot be returned.

Visit our International Terms and Conditions for more info.