Flex Seal & Hurricanes: Real-World Use, Flood Tests, and Why It’s a Must-Have—But Not a Standalone Fix
Flex Seal Flex Tape actually works this well.
If you live in hurricane country, you know preparation isn’t just about what’s in the forecast—it’s about what’s in your garage. For us, one of the first things we reach for—after the flashlights and Quick Dams—is Flex Seal.
Let’s be clear: we’re not sponsored, and we haven’t tested every Flex Seal product on the market. But we’ve used enough of them, in enough real-world situations, to tell you this:
Flex Seal works.
It belongs in your hurricane prep kit. It belongs in your house.
But it’s not a replacement for flood barriers.
Let us explain.
Real-World Flex Seal Use in Hurricane Country
Over the years, Flex Seal has earned a spot in our regular rotation of storm prep gear. Whether you’re living in Florida, the Carolinas, or anywhere along the hurricane-prone Gulf Coast, these uses might sound familiar:
1. Lining Homemade Planters
A few years ago, we built raised planters. We didn’t want soil or water leaking through the seams and damaging the structure. One coat of Flex Seal Liquid, brushed on like thick paint inside the box, sealed it up completely.
2. Hurricane Ian Ripped Our Super Gutter
During Hurricane Ian, high winds tore open a seam in our super gutter—a critical part of the pool enclosure’s water drainage system. A full repair wasn’t immediately possible, but further leaks couldn’t wait.
We grabbed a roll of Flex Seal Tape and patched the seam.
That tape held up through several more Florida downpours until the full replacement was done. It bought us time—and peace of mind.
3. Patching an Aluminum Camper Top
We have an aluminum camper shell on a work truck with a hairline crack that caused persistent leaks. We sprayed the seam with Flex Seal Spray, and the patch is still intact years later. This vehicle sits outside 24/7—no leaks.
4. Roof Repair? Not Yet—but We’re Ready
Thankfully, we haven’t had to patch our house roof yet. But we keep a tub of Flex Seal Liquid and Flex Tape in the garage, just in case. If we ever spot a drip during hurricane season, we won’t be climbing up there empty-handed.
Flex Seal Flood Protection: Real Results from Small-Scale Testing
Flex Seal offers a Flood Protection line, including liquid rubber coatings designed to be painted directly onto door frames, window sills, and other water-entry points.
We built a container and tested it under controlled conditions—no hurricane, but plenty of water exposure.
Results: It performed exactly as advertised. It repelled water, sealed gaps, and held up well during heavy rain.
Bottom Line:
✔️ It’s a solid secondary barrier.
🚫 But it’s not a substitute for sandbags or Quick Dams.
Why Flex Seal Isn’t a Standalone Flood Barrier
It’s easy to think: “If it can seal a boat, why can’t it protect a house?”
We hear that often, so let’s walk through why Flex Seal can’t replace traditional flood control methods.
Before you jump at us, we are huge fans of Flex Seal products. We would use this as a secondary barrier every day of the week, but check out this disclaimer Flex Seal provides on their page under “Important Information”:
1. It’s Not Structural
Flex Seal is a sealant, not a structural barrier. It keeps out water through gaps and cracks, but may not resist the hydrostatic pressure of rising water, or hurricane force winds.
Floodwaters pressing against a door or creeping in through foundation joints will eventually find a way through. Quick Dams and sandbags, on the other hand, absorb and redirect water.
2. It Doesn’t Divert Water
Flex Seal only protects what it touches.
Sandbags and Quick Dams are designed to redirect water flow, creating levee-like systems around entry points. They can be stacked, angled, and positioned where you need them most.
Flex Seal can’t channel or reroute floodwater.
3. It’s Surface-Only
Most of Flex Seal’s power comes from sealing visible surfaces. Unfortunately, water loves to travel beneath slabs, through wall joints, and up through porous flooring materials.
Even if your doorframe is watertight, floodwater might still seep up through the baseboards or foundation.
Use Them Together for Maximum Protection
The Flood Fighting Duo - Quick Dam and Flex Seal
Here’s where Flex Seal shines—as part of a layered defense strategy.
Use Flex Seal to prep:
Seal cracks in foundation walls and garage bases
Waterproof window sills and door thresholds
Patch sheds, gutter seams, and utility entry points
Use Quick Dams or sandbags to block and redirect:
Lay them at your garage door or front entrance
Surround low-lying areas around your home
Create a barrier along slopes or driveways
Think of Flex Seal as the inner armor. Think of Quick Dams and sandbags as your front-line troops.
Duct Tape and Old-School Tricks Still Work Too…Just Not As Good.
If you weren’t quick to jump on the wagon and the storm is approaching and Home Depot is out of everything, duct tape still work…just not as good. If you go this route, duct taped the outer ledges of your window sills during storms—not the glass (never tape windows; it doesn’t help with wind resistance), but the lower exterior trim where water collects.
It’s not pretty, but it adds a layer of protection, especially when you’re in a bind. But…you have to do this dry! It wont adhere in high humidity or wet conditions.
Also, if your sills are painted, chances are it will tear the paint off when you remove it.
Why Flex Seal Deserves a Spot in Your Hurricane Kit
It’s not just about big storms. Flex Seal comes in handy all year long. We’ve used it on everything from leaky gutters to cracked hoses to homemade planters.
If you’re building a solid prep kit, we recommend:
Flex Seal Tape – For gutters, campers, and emergency patches
Flex Shot or Caulk – Fast, clean filling of cracks
Flex Seal Spray – Versatile and easy to apply
Flood Protection Liquid – Great for low-risk areas or as a backup sealant
Final Word: Flex Seal Is a Tool—Not a Plan
There’s no single product that can handle every hurricane threat. But Flex Seal is one of those things that makes life a little more manageable during chaos.
We prep for storms every year, and if there’s one thing we’ve learned, it’s this:
Preparation isn’t a product. It’s a process.
Use Flex Seal to strengthen the details. Use Quick Dams to hold the line. Use your people—neighbors, family, and community—to cover what you can’t.
And when the alert goes out? Don’t delay.
If Waffle House is closed and the shutters are rattling—grab your go-bag and get out.
Because the best kind of seal is the one that keeps you safe and dry before the surge hits.
