Gabion walls are made up of gabion baskets. The baskets are formed from heavy galvanized wire mesh. Builders fill the baskets with rocks before using the baskets for coverings of erodible areas. Gabion baskets can also be used to construct exterior walls. These walls often serve as retaining walls holding banks or hills from shifting.
Manufacturers produce gabion baskets of various sizes. The minimum size is commonly 12 inches. Fill this size basket with rocks no smaller than 3 inches or larger than 8 inches. The bulk of the rocks in the basket should be about 5 inches in diameter. The baskets can be as large 36 inches in size, which would require stones of about 6 inches in diameter.
A wall can be constructed of a single thickness of gabion baskets piled on top of each other. This would mean the thinnest gabion wall would be 12 inches thick. Gabion wall systems commonly use larger baskets on the bottom of the wall with thinner baskets at the top.
Properly constructed, the gabion wall can extend 30 feet high. This requires following proper building procedures but does produce a wall than can stabilize a high bank of soil. The open nature of the stone-filled baskets allows water to drain through the structure and can be channeled away from the soil wall.
The base or foundation of the gabion wall provides the support for the entire structure. Walls 9 feet or more in height require a 6-foot wide concrete base. This base is sloped toward the soil wall at a 6 degree angle. This angle is continued up the wall as the gabion blocks are piled one on top of each other. This allows the baskets to maintain pressure against the soil bank.