Get matched with top retaining wall installation pros in Ossipee, NH

Most railroad tie retaining walls have a life span of 20 to 30 years, though you may need to replace your wall sooner if it’s repeatedly exposed to heavy rain, runoff, and excess moisture. Railroad ties are typically treated with creosote, which makes them much more durable than untreated wood. Though they last longer, they don’t last forever. For the most longevity, make sure your retaining wall has a sturdy base and steel reinforcements. You should also install drainage to direct water away from the wall.

Railroad ties can be good for retaining walls, but it depends on the area. They have a desirable rustic look and are durable. The problem is they’re treated with creosote, a preservative the EPA says poses a risk to humans and wildlife. Over time, the preservative seeps out of the wood and into the ground. Many areas have banned the use of creosote-treated wood on residential properties. If your area does allow it, never use railroad ties near an edible garden or drinking water source. Instead, use wood that’s treated with an EPA-approved preservative or a wood-alternative composite material.

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.