What Is A Railroad Tie Retaining Wall? How To Build, Pros & Cons

railroad tie retaining wall surrounding a small backyard garden with flowers and a small table plus chair set

When considering the least expensive ways to build a retaining wall there are a few different options. There are boulder retaining walls which can be built from boulders found on your property if you happen to have a lot of them.  But what if you don’t have any boulders and boulders are too expensive where you live?  You could use pressure treated wood. However, with the price of lumber these days it’s common for these walls to be far more expensive than expected.  Enter the railroad tie retaining wall.  

What Are Railroad Ties?

Railroad ties are wood planks 7” tall x 9” wide x 8’ long. As the name indicates, they are used underneath railroad tracks. These ties hold the tracks at the appropriate width. They also keep them stable on the crushed stone road bed.  Railroad ties are replaced on a regular basis. On regularly maintained railroad beds, perfectly good railroad ties are removed simply because they have been on the ground long enough to deem replacement with new.

What Makes Railroad Ties Good For Retaining Walls?

What makes railroad ties good for retaining walls? Railroad ties are treated with creosote.  Creosote is a byproduct of oil or coal burning, thus the dark color of the railroad ties. There are less toxic forms of creosote produced from burning wood, but most railroad ties are treated with petroleum based creosote.  Keep that in mind if you plan on gardening or are concerned with chemicals getting into the ground around your retaining wall.

Though a questionable product, creosote is an excellent preservative. It’s also the reason using railroad ties in retaining walls is popular.  Railroad tie retaining walls are built much like wood plank retaining walls. Stacking the ties on top of one another and pinning the ties to one another with long spikes. If your wall will extend higher than 2’, you should ask an engineer to provide a detail for constructing your retaining wall, as they may specify hold back methods to prevent over topping of the wall. It’s a good idea to batter back each row about an inch as your wall gets higher to prevent over topping of the walls.

railroad tie retaining wall holding back a large green garden in backyard

How To Design A Railroad Tie Retaining Wall

Railroad tie walls are considered utilitarian. They make a great solution for industrial sites, work areas, and other walls you don’t expect to see.  They are not meant to be used in obvious backyard environments. However, if you do use them there you can obscure the railroad ties with plantings. This will make them less obvious and allow them to blend into the landscape.  

Railroad Tie Retaining Wall Pros And Cons

Railroad tie retaining walls are one of the least expensive methods to build a retaining wall. Furthermore, when it comes to wood retaining walls, they railroad ties are one of the easiest to build. The hardest part in some cases is getting your hands on the railroad ties to begin with.  Occasionally, Home Depot will stock used railroad ties. You may have more success finding them sold on Craigslist or Facebook Marketplace from time to time. Railroad ties are very heavy material. You’ll probably want to bring a friend when it comes to moving them around.

How To Build A Railroad Tie Retaining Wall

If you consider building a railroad tie retaining wall, you need to follow the basic rules of all retaining walls.  First, excavate for a level footing. The key is to make sure you excavate far enough into the hillside to allow for properly draining backfill to be placed behind and under your wall.  Next, make sure you are placing your spikes at the specified intervals, usually 8-12” apart along the retaining wall length.  You’ll need a long drill bit to drill the pilot holes for the spikes. Make sure you are backfilling with good quality material so the earth doesn’t retain moisture behind your retaining wall.  And last but not least, enjoy your newly leveled yard!

Railroad Tie Retaining Wall Summary

The railroad tie retaining wall is a solid choice for its inexpensive nature and ease to build. You may have difficulty finding enough railroad ties to complete the wall, but otherwise your project will succeed. Review our how to build section for some important advice. If you’re not sure about a railroad tie retaining wall, consider a boulder retaining wall. These two options are your best bets when it comes to affordable retaining walls on your property.