Sandbag Installation Instructions.
Building a Sandbag Wall.
Engineers typically recommend building a dike with a base width that is two to three times the height of the dike or berm. For example, a 4ft high wall would require a base width of between 8ft and 12ft. Most sandbags are 24” long, 14” wide and about 4” high. Each 2ft of finished dike length requires 1 bag, each foot of height requires 3 bags, and each 2.5ft of width requires 3 bags. Bags should be positioned in the direction of the expected flow of water, for water redirection, or with the long side facing the approaching water.
The charts below calculate the estimated number of sandbags and sand needed for 100 linear feet of dike.
Equipment & Personnel.
We recommend using a #2 rounded point shovel, with a D grip and a straight shaft as this fits best with the opening size of the sandbags. We suggest always using gloves when filling sandbags, to protect your hands.
Filling sandbags by hand tends to be a labor intensive proposition, so its best to plan to have enough volunteers or workers to construct your wall in the available time. Always protect your back and do not throw sandbags.
2 people working together with a shovel and tying off the bag (assuming integrated ties) can usually fill and position 12-15 sandbags per hour. It would take 2 people between 45-50 hours to fill and position enough bags to build a 100ft long dike that is 1ft high with a recommended 2ft width (or 2 bags wide).
Note: It is possible to purchase sandbag filling machines that automate the sandbag filling process. Some machines can fill upwards of 15,000 bags per 24 hour period.
Number of Sandbags Needed.
It is important to get a sense in advance of how long and how tall of a dike you may need to build, as it is often impossible to get enough sandbags once an emergency situation is developing. As such, we recommend having enough sandbags and a source of sand readily available in advance of any flood situation.
Sandbags are a cost effective way to protect yourself against a possible flood event as the bags themselves are quite inexpensive and they can be stored compactly for future use. Most public works departments and many construction supply yards have stores of sand on hand, suitable for use if needed.
Wall Height w/Base 2x Height
ft Tall
ft Tall
ft Tall
ft Tall
Wall Height w/Base 3x Height
ft Tall
ft Tall
ft Tall
ft Tall
Number of Sandbags
600
1700
3000
5500
Number of Sandbags
600
2100
4500
7800
Bags Required for 100 Linear Foot Wall
Amount of Sand or Fill Needed.
For erosion control applications, we suggest using gravel, however for flood control applications, sand is considered the best fill material.
1 cubic yard of sand will fill approximately 100 - 14” x 26” sandbags. We recommend filling to a weight of 30 lbs each, which is about 1/2 to 2/3 full, to allow some flexibility and to prevent seepage or leakage due to gaps between bags. Each sandbag will hold about 0.4 cubic feet of sand when filled to the recommended amount.
Note: Do not overfill sandbags, or they will not conform to adjacent bags or the ground surface and will be difficult to handle and move.
Fill Required for 100 Linear Foot Wall
Wall w/Base 2x Height
ft Tall
ft Tall
ft Tall
ft Tall
ft Tall
Wall w/Base 3x Height
ft Tall
ft Tall
ft Tall
ft Tall
ft Tall
Cubic Yards of Sand
6
18
38
65
100
Cubic Yards of Sand
7
25
54
95
145
Additional Precautions.
Plastic Sheeting
Because sandbags are not completely sealed and some leaks can be expected, it is possible to add a layer of plastic rolled sheeting (available in most home stores) on top and on the water side of a sandbag wall. It is important to weigh down the sheeting with additional sandbags, to prevent the sheeting from blowing away in heavy winds and to create a proper seal between it and the ground below.
Pumps
While a sandbag wall is an effective way to protect against rising floodwaters, rain and some seepage may allow water to penetrate behind a sandbag wall. As such, it is recommended to have a simple water pump (a pool cover pump is often suited) to drain excess water that may accumulate behind the protecting sandbag wall and to pump it outside the perimeter. Remember that pumps can fail in the event of an electric outage and other precautions should be taken to prevent and drain water accumulation behind the dike, berm, levee or barrier.
