How To Repair Railroad Tie Retaining Walls

Railroad ties are heavy-duty wood timbers typically measuring 7 by 9 inches and 8 feet, 6 inches long. They are treated for rot- and pest-resistance, usually with creosote and other toxic treatments. The U.S. EPA does not approve railroad ties containing creosote for any residential use. It is not illegal to have an old railroad tie retaining wall on your property, but depending on local laws, it may be illegal to build or repair a wall using railroad ties. Therefore, it is important to assess the wall carefully and determine the best and safest approach to repairing or rebuilding the wall.

There are a few factors to consider when determining next steps for your retaining wall: the wall height, the amount of damage and the role the wall plays in your landscape. If the wall is less than 3 feet tall and is not performing a critical function, such as holding back earth from the house or its foundation, you can consider repairing the wall yourself. If the damage is significant, it might be best to replace some or all of the wall with new landscape timbers (not railroad ties) or other retaining wall material. Before doing any work on a railroad tie wall yourself, contact your city for recommendations on the handling and disposal of old railroad ties.

Retaining walls that are taller than 3 feet and/or play an important role in the landscape (including controlling drainage) should be assessed and repaired or replaced by a professional. Tall retaining walls or those directing water require engineering expertise, and failure of old or new walls can lead to significant damage to a home or landscape.

Professionals can take several different approaches to repairing or replacing an old railroad tie retaining wall. The first thing a professional will do is assess your wall. If it cannot be repaired, they will need to remove the composite materials in a manner that complies with local disposal laws. This may also require the use of heavy equipment on your property. Homeowners will need to pay for both removal and disposal costs.

If repairs alone will be appropriate, the professional you work with will probably start by removing vegetation growing around the wall. Trees, shrubs and other plants may not only in the way, but they also could be contributing to the deterioration of the wall due to moisture and root systems. Then, the pros will set up a system of supports or scaffolding to support the wall during their repair work.

Pieces of railroad ties at the top or edges of your wall can probably be replaced by your professional team (albeit with lumber of another type). Pieces in the middle can be supported with soil nails, fencing or geogrid to help support the wall and prevent further damage. Though it would not be aesthetically pleasing, a metal mesh net can also be applied to the surface of the wall to keep it from falling. Professional repair engineers or landscapers would attempt to maintain the staggered appearance of your wall with any pieces they integrate in accessible portions.

If the wall did not have proper drainage, this may have been the source of the damage. Professionals will make sure that the wall is sitting on a tamped bed of gravel. If the wall was not built on this gravel to begin with, it's unlikely it can be added now. However, drainage holes can be drilled in the wood throughout the wall to facilitate water runoff.

A professional will also assess the slope of your wall. It should have been built to lean against the slope behind it. This is known as battering. If your current retaining wall is not anchored to the slope, your repair team may be able to adjust its battering as they anchor it to the slope.