Filling gaps, cracks, and holes just got easier with Flex Foam. This super flexible, expandable foam sealant fills openings around your home to help insulate and seal out moisture, drafts, pests, and noise.

In this guide, we'll cover the right way to prep, apply, and store Flex Foam, along with key tips to help you have a successful foam experience.

What Is Flex Foam?

Flex Foam is a super flexible, expandable foam that can seal all types of openings. It won't crack or break like traditional foams, and cures to a flexible rubber that moves with shifting surfaces. Flex Foam cures to a bright white finish and can be trimmed, sanded, painted, or stained for a clean, professional look.

Where Can You Use Flex Foam?

Flex Foam is great for a variety of applications, both indoors and outdoors.

• Plumbing and HVAC penetrations
• Window and door frames
• Pest entry points
• Areas where sound dampening is needed
• Basement gaps and penetrations
• Crawlspace gaps and penetrations
• Pipe insulation
• Remodeling projects
• Brick and concrete gaps
• Soffits and fascia
• Spigots and other exterior penetrations
• Roof joints, siding gaps, and much more

Flex Foam bonds to most materials, including wood, brick, metal, stone, vinyl, PVC, and more.

How To Use Flex Foam

Before getting started, read all directions and safety information on the label. Always wear eye protection, gloves, and proper work clothing when using Flex Foam, as cured foam is difficult to remove.

1. Prepare the Surface

Make sure the application area is clean, dry, and free of grease and oil.

2. Shake the Can

Shake the can for 60 seconds. Immediately after shaking, attach the straw applicator. Before starting your project, test the pressure and expansion rate on a piece of scrap material to get a feel for how the foam dispenses.

3. Invert the Can

For best results, turn the can upside down while using Flex Foam. This helps reduce clogging and maximizes the amount of product you'll get out of each can.

4. Apply Flex Foam

Apply Flex Foam into the gap, crack, or hole, but only fill the opening up to 50%. Do NOT overfill. The foam will continue expanding, so leaving room for that expansion is an important part of the application process.

5. Let the Foam Cure

Flex Foam becomes tack-free in approximately 10 to 15 minutes, and fully cures in 8 to 12 hours.

6. Trim, Sand, or Paint

Once fully cured, Flex Foam can be trimmed and sanded for a clean, professional finish. Its bright white surface can also be painted or stained to better blend into the surrounding area.

How To Clean Up Flex Foam

Fresh, uncured foam can be removed immediately with a multipurpose foam cleaner or cleaning wipe. Cured foam can only be removed mechanically; it cannot be dissolved once cured.

How To Store Flex Foam

Store Flex Foam upright in a cool, dry place away from direct sunlight. Do not allow the can to freeze or be exposed to temperatures above 120°F (50°C).

After use, leave the applicator nozzle attached. The foam remaining inside the nozzle will cure, forming a plug for storage. Before your next project, remove the old nozzle and attach a new flexible applicator nozzle. Additional nozzles are sold separately.

Tips for Best Results

• Test the surface first. Flex Foam may not be compatible with some plastics, so apply it to a small, inconspicuous area first if you're unsure about the surface.
• Don't overfill. Remember that Flex Foam continues to expand after it is dispensed. Fill the opening only up to 50%.
• Keep the can upside down while dispensing. This helps provide complete delivery and reduces the chance of clogging.
• Apply at the right temperature. For best results, apply Flex Foam at an optimum temperature of 68–77°F (20–25°C). It is approved for application at temperatures from 32–95°F (0–35°C).
• Give it time to cure. The foam will be tack-free after 10 to 15 minutes, but wait 8 to 12 hours before trimming, sanding, or painting.
• Add extra protection when needed. For waterproof and UV protection, apply a topcoat of Flex Seal Spray or Flex Seal Liquid after the foam has fully cured.
• Store it properly. Keep the can upright in a cool, dry place between 41°F and 77°F. Do not expose it to freezing conditions, temperatures above 120°F, or direct sunlight.

Now you know how to seal and protect your home with Flex Foam. Grab a can of Flex Foam today and get started on your next project or repair.