The Flood barrier
Meet FlowStop
How does it work?
The FlowStop flood barrier consists of two main parts: an upper cushion and a lower cushion.
The upper cushion is designed to push sideways against the wall. The intense pressure locks the device in place, creating a roof for the lower cushion.
With the upper cushion inflated, the lower cushion is trapped between the ground and the upper cushion. As it inflates, it expands and presses down against the ground, forming a water-resistant seal.
Why is it better?
Is it strong enough?
A rigid barrier transfers impact energy directly into its frame. A hard hit from storm debris—a floating branch, driftwood, or displaced equipment—can dent or deform a metal panel. Because metal doesn't 'bounce back,' these deformations often break the seal at the critical moment it's needed most. Once a rigid panel is bent, it typically cannot be repaired and must be replaced entirely.
Inflatable barriers, however, respond to impact like a shock absorber: they deflect and absorb the force, then return to their original shape without structural compromise. In the rare event of a puncture from extremely sharp debris, the resilient material can be easily patched in the field—much like a high-end whitewater raft—restoring the barrier to full strength immediately.
To know more about this topic, check out our blog article here.
FlowStops are made of PVC, making them resistant to debris, temperature changes, wind, and strong impacts. FlowStop is built using drop-stitch technology, which is commonly used in inflatable paddleboards.
This allows us to apply over 15 PSI of pressure inside the cushions, creating an impressively strong barrier.
This pressure fills in imperfections on the surfaces it contacts, forming a water-resistant seal.
Sizes
Width
We custom-make FlowStop to fit the width of your opening up to 275". However, since FlowStop units wider than 10 feet become heavy and difficult to install, we recommend splitting them into smaller units using a connecting removable posts.
Depth
The depth of your FlowStop depends on its width; the wider the unit, the thicker the barrier. If your opening lacks the required depth, we can install custom-made posts to create the proper depth.
See posts in our accessories section here.
Height
The double chamber FlowStop comes in 4 heights (31.5", 35.5", 39.5" and 47.5")
Choose the appropriate height to meet the risk based on where you live.
If your FlowStop is:
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Less than 60" wide: the minimum height is 31.5”.
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More than 60" wide: the minimum height is 39.5”.
Split a long FlowStop into
smaller ones
FlowStop is praised for being lightweight and easy to install. FlowStop wider than 10 feet becomes significantly heavier and more difficult to install. So we recommend splitting them into smaller ones.
FlowStop posts make installation easier and help adapt the system to different opening sizes.
You can choose between two options:
Straps on Long FlowStops
Depending on the surface of the opening and the height and width of your FlowStop, additional straps may be required. The straps are anchored to the ground with permanent bolts. See tutorial for more information.
Wall Surfaces
FlowStop works on most surfaces.
The gasket can fill up and seal up to 0.30 inches of gaps or imperfections on your wall.
Do not use it on surfaces that are too slick.
Do not use it against drywall.