Sleepers can be laid directly onto firm ground, however it's recommended that at the very least a bed of sand or aggregate is used to assist drainage and provide a firm footing. Purists will always insist on a concrete bed, however if the wall is additionally supported by posts then this is not always necessary.
We suggest using gravel or sand to provide drainage and a level surface when laying sleepers directly on soil. When creating taller retaining walls using a large number of sleepers, a solid foundation is integral for the overall stability.
You can use DPM on the rear of the timber, and pea gravel backfill directly behind sleepers. The pea gravel will allow a free draining area behind the wall. You could also add a length of land drain wrapped in geotextile membrane, to keep fine particles of soil out of pipe.
You can either opt for concrete, sand or gravel foundations or lay the sleepers on the soil with no official foundation. For the latter option, make sure you put down a waterproof sheet under the sleepers to avoid them soaking up moisture from the soil.
Crushed stone or gravel: This will serve as the foundation for your wall. It aids in giving your sleepers stability and drainage. You'll line the base of the wall with landscape fabric to stop dirt and other debris from getting into the gravel layer.
Drill and screws: Secure the sleepers together firmly. Steel beams or RSJs (if required): For additional support in higher walls. Porous pipes or drainage materials: Consider drainage behind the wall to reduce water pressure. Backfill material: Use excess soil or gravel behind the wall for stability.
Retaining walls and raised beds are just two ways that these unique timber pieces allow you to enhance your garden projects. But the question is – can you lay railway sleepers on soil? The answer is – Yes you can.
Sleepers are best constructed on a firm and level surface such as soil, grass, decking or concrete, however, you should still use a spirit level to ensure the surface is as level as possible. Depending on your project, you may wish to use sand, cement or timber offcuts to level things out.
Over time, especially in contact with soil and moisture, hardwood sleepers will also break down. They may last longer than softwoods, with a lifespan of 10-15 years if properly treated, but they are also more expensive.
You should also know the size and length of your steel posts, calculating how deep they need to be installed. Generally speaking, steel post depth should equal the wall's height plus 100mm for cover on steel. So if your wall is 3.0 metres high, then your steel posts should be 3.1 metres deep.
Providing Sufficient Drainage
Correct drainage is one of the essential elements to focus on when building a sleeper retaining wall, ensure that there is a sufficient gap behind the wall to install all necessary drainage before you commence wall construction.
Average Cost of Concrete Sleeper Retaining Walls
Starting at $480 to $680 per square metre, including standard design, basic excavation, and installation.
A simple method is to create a drainage tube with a length of permeable membrane and gravel. Before back-filling the soil behind your retaining wall, lay a length of permeable membrane at the base of the wall then cover half the width next to the wall with a 20cm wide and 20cm deep layer of large gravel or ballast.
The use of gravel or sand to secure sleepers is a popular alternative to concrete. Whether you're using sleepers to form new edging around your landscape or are building a raised planting bed, gravel and sand foundations are certainly worth considering.
In Scotland, a sleeper wall is defined as a load-bearing element and therefore should be provided with a suitable foundation.
Concrete blocks are a low-cost option for constructing a retaining wall. They are strong, long-lasting, and come in various sizes and forms to meet your design tastes.
The maximum height of a sleeper retaining wall is 2.8 metres. And the higher the wall, the more engineering support is required. This could mean installing additional steel posts for your wall's reinforcement.
Railway sleepers can be laid on soil, but it's important to prepare the ground properly before installation. First, remove any debris and level the soil to create a flat surface. You're best removing any grass or weeds then adding a base layer of gravel or sand to help with drainage.
Clear the area of all unwanted vegetation and material and then dig a shallow, level trench to allow for bedding material. Usually you would allow 3-4 courses in height and start by bedding the first sleeper onto a semi-dry concrete mix laid in your trench.
If you wish to add finishes or other treatments to your sleepers, this is the best time to do so. Laying sharp sand into your channels or in the dug area of your pathway will ensure each board has a nice even foundation. Pour in a layer of around 25mm and pack it down using one of your sleepers or a tamper.
Considering the type of soil
If you have well-draining soil, a layer of gravel or crushed stone can be an excellent option. Garden design with sleepers and gravel offers various benefits. Gravel allows for proper drainage, preventing water from pooling and potentially causing damage to the sleeper structure.
Fill around the sleeper with soil or sand to secure it in place before moving onto laying the next one. To fix railway sleepers to the ground, use spikes or screws designed for outdoor use to ensure they remain stable over time.
You might want to put a layer of concrete, sand or aggregate in first, but this isn't always strictly necessary. Continue around in the same way until you've got the bottom layer in place. At this point, it's worth using a spirit level to make sure all your railway sleepers are lying flat.