Treated pine sleepers are a great choice for building a retaining wall as they're very strong, easy to cut and fabricate, and have been treated to stay waterproof and to resist insects and other damage. Building your own retaining wall with these sleepers is not very difficult, with a few tools and a bit of knowhow. Consider a few tips to help you get this done.
1. Open versus closed face
For a small retaining wall, you probably want a closed face style, which is exactly as it sounds. Each sleeper is stacked on top of each other so that the wall is solid, and this holds back the most amount of moisture and soil. These sleepers are attached to end posts, just like sections of a fence.
Larger walls may need to be open faced, which is when you purposely leave a gap between each pine sleeper. This allows some moisture to seep through. Allowing some moisture to get through the retaining wall will take pressure off of it, and also ensure that your retaining wall doesn't lead to soil erosion.
A land surveyor can help you to determine if your retaining wall should be open faced, or as a general rule, keep it open faced if it's taller than 0.9m or 3 feet. To make an open faced wall, you place a section of cut pine sleeper in the opposite direction of the wall slats as a spacer, and attach them to the slat underneath. This creates the gap.
2. Installing end posts
The end posts should be set in concrete and not just buried, as this is needed to ensure that they will stay sturdy. Make sure your concrete mix is moist but not runny, so that you can create a compact seal around the end posts. It's a common mistake for homeowners to start constructing the rest of the wall before the end posts are set, so wait a few days before you add in the horizontal sleepers so you know the concrete has dried properly.
3. Avoiding slopes
Using string and a carpenter's level or laser level, you can create a guide for the sleeper posts you add as the retaining wall itself. If the ground slopes, you might want to actually create slopes in the wall but you need to ensure that the slopes are all even. This is where the carpenter's level is useful; note the angle of the first wall and maintain that same angle along all the sections of the wall. Failing to do this will mean a retaining wall that looks as if it's sagging in one section.
Contact a company like Australian Treated Pine to learn more.