Please take some time and read our filling and usage instructions. The following information is provided to assist you in filling sandbags and constructing barriers. Sandbag Express is not responsible for the contents or results.
Building Dikes: How To Fill And Position Sandbags
Site Selection
Select the site for the dike, making the best use of natural land features to keep it as short and low as possible. Avoid trees or other obstructions which would weaken the structure. Do not build the dike against a basement wall. Leave about 8 feet of space to maneuver between the dike and buildings. Remove ice and snow from the strip of land you’ve selected down to the bare ground if possible.
Sandbag Needs
The number of bags required for 100 linear feet of dike is as follows:
- 800 bags for 1-foot-high dike.
- 2,000 bags for 2-foot-high dike.
- 3,400 bags for 3-foot-high dike.
Filling and Positioning Sandbags
To view detailed diagrams on proper filling of sandbags, click here. In addition, here are a few helpful tips:
- Fill bags approximately half full of clay, silt or sand. Do not tie.
- Alternate direction of bags with bottom layer lengthwise of dike. Lap unfilled portion under next bag.
- Tamp thoroughly in place.
- Build the dike three times as wide as high. For example, if the height is 3 feet, make the base 9 feet.
Sealing the Dike
Seal the finished dike to increase its water tightness. To seal the dike:
- Spread a layer of earth or sand 1 inch deep and about 1 foot wide along the bottom of the dike on the water side.
- Lay polyethylene plastic sheeting so the bottom edge extends 1 foot beyond the bottom edge of the dike over the loose dirt. The upper edge should extend over the top of the dike. This sheeting is available from Sandbag Express. It should be about 6 millimeters thick. It comes in 100-foot rolls and is 8 or 10 feet wide.
- Lay the plastic sheeting down very loosely. The pressure of the water will then make the plastic conform easily to the sandbag surface. If the plastic is stretched too tightly, the water force could puncture it.
- Place a row of tightly fitting sandbags on the bottom edge of the plastic to form a watertight seal along the water side.
- Place sandbags at about 6 foot intervals to hold down the top edge of the plastic. Place boards or dirt between these sandbags to prevent winds from disturbing the plastic. As you work, avoid puncturing the plastic with sharp objects or by walking on it.
Additional Resources
- Additional Sandbag Usage Instructions and Diagrams (click here)
- Flood Fighting (click here)
- Debris and Erosion Control (click here)
