Knowing how to build a sandbag wall correctly ensures that the wall will serve its purpose in the event of a flood. Placing the bags correctly helps the wall hold back the flood waters to prevent them reaching a building or grounds you want to protect. The hardest part of placing the sandbags is carrying the weight of each bag. However, with assistance from at least one other person, you can easily build a wall to hold back the water.
Buy sandbags at a local hardware centres such as B&Q, Homebase or Wikes. If you prefer to order sandbags online, Flexible Packaging carries different types. Determine how many bags you would need to complete the wall.
Buy sand. You can find sand at a local hardware shops or construction material outlets that carries gravel and sand. Some garden nurseries may also carry sand for filling the sandbags.
Hold open a bag, while another person uses a shovel to load the sand into the bag. Fill the sandbag to 10 cm (4 inches) from the top so that you will have a flap at the open end. If you're using a drawstring bag, close the bag by pulling the string. Otherwise close the bag as directed by the manufacturer.
Place a plastic tarpaulin on the ground and halfway up a home exterior wall if using the sandbags as a barrier in doorways and basement window wells. If you're building a wall away from a building, you won't need the tarpaulin.
Place the first row of sandbags on the ground. Make sure that each one is tight against the next. If the sandbag has a flap on one side, place the flap under the next sandbag.
Start the next row on top of the first. Stagger the placement of sandbags, as in the figures.
Continue building the wall upwards until you reach the height you need. Stagger each row.