How To Seal Windows

Our video below will maximize your success when preparing for a flood using the Flex Seal Flood Protection line. Windows can vary in shape and design, so it is important to seal any area where water may enter.
Always follow evacuation orders. Heed all directions from local government and emergency management officials. Watch our introductory video before starting.
Products Used:
Flood Protection Paste (Cartridge)
Flood Protection Liquid
Tools Used:
• Caulk Gun
• Flex Gap Filler Tool
• Paint Brush
• Putty Knife
• Protective Gloves
• Eyewear
Flood Paste in a Cartridge is the base coat for your first layer of protection. Use a gloved finger, Flex Gap Filler tool, or similar tool to push into all seams and openings to help create a watertight seal. Always be cautious of any sharp objects that may cause injury.
Apply Paste
Note: For basement windows, please refer to 'How To Seal Crawl Spaces, Basement Windows, and Pet Doors'.

Apply an even bead of Flood Paste directly into the seams where windows open, where windowpanes come in contact with the frame, and where the window meets the casing.

Apply an even bead of Flood Paste to seal where the window casing meets the exterior wall. Use a gloved finger or our Flex Gap Filler tool to push the Flood Paste into all seams and smooth out.
Additional Layers
If you applied Flood Protection Paste in thin, even layers, you should expect it to be dry to the touch in two to six hours. Next, we recommend applying additional coats of our Flood Protection Paste as needed.

Follow the same application process as the first layer, but each individual coat that you apply should be wider and overlap the previous layer of Flood Protection Paste.

Once the doors have been sealed and are completely dry and you already have multiple layers of Flood Protection Paste, we recommend using our Flood Protection Liquid as an additional layer of protection.

When applying our Flood Protection Liquid, use your brush and apply it directly on top of our Flood Protection Paste, making sure you overlap your final coat — this will help cover any pinholes or openings that you can't see.

Remember you want to make sure all the flood protection products are fully cured before a flood arrives.

For additional help, click on one of our how-to options below, or call us at:
833-4-A-FLOOD (833-423-5663).

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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.
Contact Us
Flood Protection Products Support
‍Our dedicated Flood Protection Product support is here when you need it. Whether you have questions about our products, or need help ordering, our experts are ready to help.

You can also watch our informative series of step-by-step videos by visiting
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