How to Keep Flood Water Out of Your House With Sand Bags
- 1). Obtain untreated burlap bags from a feed or hardware store. Use the following equation to determine how many bags are needed per linear foot of the wall you are planning to build.
N = (3 x H + 9 x H x H) / 2
N = Number of bags needed for each linear foot of the wall
H = Wall height (in feet)
For example, if you wanted to build a 100-foot wall with a height of 2 feet, the equation would look like this:
N = (3 X 2 + 9 X 2 X 2) / 2 = 21 bags per linear foot of wall
21 bags X 100 linear feet = 2,100 bags
The U.S. Army Corps of Engineers recommends that the base of the wall should be three times the actual height. - 2). Determine the number of cubic yards of sand you will need to fill the bags halfway. A cubic yard of sand is 27 cubic feet. It will take 0.4 cubic feet of sand to fill a 14-by-24-inch bag halfway. Each cubic yard of sand will fill approximately 67 bags halfway.
- 3). Clear the area where you are planning to build the wall. Remove any rocks or other debris. Leave at least eight feet between the house and the wall for observation purposes as well as other necessary activities.
- 4). Wear safety glasses if it's a windy day, and fill each bag halfway with sand. Working in pairs will bring you the best results. One person should hold the bag, and then the other person should shovel the sand into the bag. The person holding the bag should bend at the waist until his elbows rest on his knees in order to reduce the risk of injury. Fold each bag to form a triangular end.
- 5). Place the bags lengthwise and parallel to the flow of the water. Place the closed end, or bottom, of each bag on the folded end, or top, of the preceding bag and stamp it into place or walk across it to eliminate any unnecessary space.
- 6). Stagger the bags when building additional levels. This will help the wall achieve stability. Place clusters of sandbags approximately every five feet at the base of the wall to promote stability.