How To Build A Timber Retaining Wall With Steps

Building a timber retaining wall is not as hard as you may think. You can make one out of railroad ties or cut-off logs, but the best material for building a retaining wall is pressure-treated lumber. Pressure-treated wood will last at least 20 years, making it perfect for your DIY retaining wall. A timber retaining wall can be installed on a slope that’s difficult to manage and can also help prevent soil erosion. Once completed, your new garden feature will keep your yard looking great for years to come.

Planning the retaining wall

It’s time to start planning your retaining wall. Here are some of the things you should consider when figuring out the size and shape of your wall:

  • How many materials do I need?
  • What kind of soil will be going into it?
  • What is the location for this particular project?

Once you have these questions answered, it’s time to move onto step two: choosing materials for your retaining wall.

How to lay out a timber retaining wall

  • Set your slope angle
  • Decide on the size of your retaining wall
  • Calculate how long you want your retaining wall to be
  • Calculate how high you want your timber retaining wall to be
  • Consider ground conditions and what materials will be used for this project (you can use concrete blocks, sandbags, etc.)

Retaining wall foundation

Before you start digging, it’s important to know how deep your retaining wall foundation should be. This varies depending on the soil type and height of your wall.

If you’re building a small retaining wall that is no more than 6 feet tall (1.83 meters), 1 foot (30 cm) of concrete will suffice as a base for 8-12 inch sleepers. For taller walls, increase this depth by an additional 6 inches (15 cm).

To determine how much soil you’ll need for all of your retaining wall bases, multiply their combined length by 1/2 their width and add this amount to twice their combined height. Then multiply this total by 0.0043125 (the cubic volume of one inch per foot). This gives you an approximation of the overall cubic footage needed for each base layer; if necessary, adjust your measurements accordingly so they don’t exceed what will fit in one dumpster load

How to build a timber retaining wall frame

The next step is to build a timber frame to support the wall. This is a critical part of the construction. The soil will eventually support all the weight of your retaining wall, but only if it has something solid on which to sit. The timber frame provides just that: it provides a stable base for your retaining wall and allows you to install it with confidence.

You can use standard wood screws or nails (depending on the type of wood) to secure the timbers together at each corner and every few feet along each side. It’s important not to over-tighten these screws or nails; they should be tight enough so they don’t come loose easily, but not so tight that they crack or split any of your timbers, which could lead them becoming weak points in your overall structure later on down the road when things start getting heavy

How to install the posts for a timber retaining wall

Attach the posts to the sleepers, beams and concrete.

The first step in installing your timber retaining wall is to attach it to the sleepers with screws. If you have a traditional slab foundation, work from the bottom up so that there are no gaps between each section of sleepers (this will make attaching and concreting later on a lot easier). Work from one end of your shed or deck and screw them into place about every 15cm apart for extra security. You can also install temporary posts as a guide for where you will be placing them permanently once your walls are complete.

Once all four sides of your timber retaining wall are attached with screws, check that they’re level across both their widths and heights – if not then adjust using shims until they match perfectly up against each other – this ensures that they’ll stay tightly together when you start pouring concrete over them later on too

How to assemble the sleepers for a timber retaining wall

When building a timber retaining wall, the sleepers form the first step of framing and are critical to your overall design. Assemble your sleepers based on their size and shape, which will determine how many posts you need to frame them.

For example, if you’re building a timber retaining wall with sleepers that are 36 inches long by 16 inches wide and 12 inches high (seen here), then you’ll need to frame each sleeper with four posts: one at each end for stability and two in between for added strength. Once all of these posts have been set into place, begin laying out blocks between them until your entire structure has been completed without any gaps or overlapping pieces.

Attaching the beams for a timber retaining wall with steps

To attach the beam to a post, you’ll need to drill three holes through one side of each timber sleeper and into the post.

Drill holes at least 10mm deeper than the depth of your lag bolts.

Insert a lag bolt through each hole and tighten until snug.

Building stairs for your timber retaining wall

Once your retaining wall is complete, you can begin building the stairs.

  • First, assemble the sleepers to make a stair tread. The treads should be as long as they need to be, but they should all be the same length.
  • Next, cut and attach them to the stairs with a hammer and nails – see here for more information on this process.
  • You may have already put in a beam that’s attached to posts at either end of your timber retaining wall; if so, you can use this beam as an attachment point for your stairs. Otherwise, use another 2×4 board or similar material as an attachment point (we recommend using screws instead). Simply screw it in place so that one side of each step connects seamlessly with it – no need for any gaps or cuts

Filling in gaps and attaching the beam to the post.

Next, use a wooden spacer to fill in the gap between the beam and post. Then attach a wooden block to the beam using nails or screws. Make sure you’re using proper masonry or wood screws for this step, as their heads need to be flush with the surface of your timber retaining wall so that they don’t interfere with attaching your lattice panels later on.

Next comes leveling: use a spirit level (or even just two pieces of scrap wood) to make sure that your beam is perfectly horizontal before driving it into place with a mallet.

Think about how you want your garden to look and how you want it to function, then start building

  • Think about how you want your garden to look and how you want it to function, then start building! Make sure all of your measurements are accurate for the best results.
  • You can do this yourself, but if you’re not too handy with tools or have never built a retaining wall before, consider hiring a contractor or landscaper to help out. The process is still very straightforward even without firsthand experience; just make sure that whoever you hire has experience building retaining walls and knows what they’re doing when it comes time for digging holes or mixing concrete. If possible, talk with someone who has had experience with hiring contractors before so that they can give advice on how best to go about finding one who fits within your budget.


This article has given you all the information you need to build a timber retaining wall with steps. Remember to keep it simple and make sure you’re safe.

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