Get matched with top retaining wall installation pros in Paris, MO

Yes, to build a retaining wall, a permit is required. Similarly, any repairs or modifications to an existing retaining wall require permits. If the planned wall measures higher than 4 feet, most municipalities require designs and permits come through a licensed engineer. In some locations, if the wall is shorter than 4 feet, a permit may not be required. For the requirements in your area, contact your local government.

Small retaining walls still require a foundation of some kind, typically a concrete footing. This helps to ensure the wall is structurally sound and prevents the ground from shifting over time, especially during those winter freeze/thaw cycles. The footing helps spread the weight of the wall and the load it carries over a larger area of the ground, thus assisting with stability. This is true of small retaining walls, larger rock garden walls, and the like. 

Generally speaking, a retaining wall should be between 3 and 4 feet high, depending on variables such as the wall-building material, the purpose of the retaining wall, and more. If you want your retaining wall to be taller than 4 feet, check with your local building ordinance office for the maximum allotment. You may also need a special permit for retaining walls over 4 feet tall.

The longevity of flood walls depends on how they were constructed, but most wood, gravel, and cement flood walls last 10 years. While aluminum flood walls may cost far more initially, they can be a good investment as they can last decades and will not be damaged by exposure to the elements.