How Many Sandbags for a Garage Door?
How Many Sandbags for a Garage Door?
Garage doors are the largest and most vulnerable flood opening on most homes. They're wide, sit at grade level, and their weatherstripping is not designed for water pressure. Sizing the sandbag count correctly is critical — undersizing means water gets past the barrier, oversizing wastes money.
Quick answer for a garage door
The exact number of StormBag sandless sandbags you need to protect a garage door depends on the width of the opening and the expected water height. Here are the specific counts:
Single garage door
| Expected water height | Bags needed | Recommended kit |
|---|---|---|
| 4" | 9 | 10-Pack Box ($99.99) or Single-Wide Garage Kit |
| 8" | 18 | 25-Pack Box ($239.99) or Single-Wide Garage Kit |
| 12" | 27 | Single-Wide Garage Kit ($149.99) × 2 or bulk order |
| 16" | 44 | Single-Wide Garage Kit ($149.99) × 2 or bulk order |
| 24" | 62 | Single-Wide Garage Kit ($149.99) × 2 or bulk order |
Double garage door
| Expected water height | Bags needed | Recommended kit |
|---|---|---|
| 4" | 16 | 25-Pack Box ($239.99) or Double-Wide Garage Kit |
| 8" | 31 | Double-Wide Garage Kit ($239.99) × 2 or bulk order |
| 12" | 47 | Double-Wide Garage Kit ($239.99) × 2 or bulk order |
| 16" | 77 | Double-Wide Garage Kit ($239.99) × 2 or bulk order |
| 24" | 108 | Double-Wide Garage Kit ($239.99) × 2 or bulk order |
How the count is calculated
StormBag sandless sandbags measure roughly 14 inches wide and 4 inches thick when hydrated. The formula: (opening width in inches ÷ 14) × (water height in inches ÷ 4), rounded up, plus 10% overage for irregularities and a stability row on top for water heights above 12 inches. This is the same USACE-derived formula the StormBag Sandbag Calculator uses.
Deployment notes for a garage door
For garage doors, height matters more than for interior doors because water can bow the door itself inward under pressure. Plan for 12-16 inches of water minimum if you're in a flood-prone area; storm surge and flash floods can peak higher.
Get an exact count for your specific opening
The table above uses standard opening widths. If your opening is slightly different — a non-standard patio door, an oversized garage, a custom basement window — use the calculator to get the exact bag count for your measurements.
StormBag Sandbag Calculator
Enter your opening width and expected water height. Get the exact bag count and a kit recommendation.
Open the Calculator