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Retain-iT® Retaining Wall Post System

Whether you want to build a garden bed, prevent soil erosion, improve drainage, or add some character to your yard, our Aussie-designed Retain-iT® retaining wall posts are really something! Simply drop in some natural wood sleepers for a strong, long-lasting, and beautiful natural barrier. Build your timber retaining wall tall or just add a layer or two; it’s up to you!

Retaining Wall Q&A: Level Up Your Landscaping Skills

Looking to level up your outdoor spaces? A retaining wall or two will help you do it, metaphorically and literally!

We love these brilliant, practical barriers here at Jack, and we make building them easy with our Retain-iT® retaining wall systems. Even beginners can give it a go.

Don’t know much about them? Well, sit down and dig in as we answer some of the most common questions we get asked, from materials to how to build them!

What is a retaining wall?

This one’s pretty basic, but it’s good to start at the start.

A retaining wall is a solid structure designed to support soil on a slope. It not only stops erosion in its tracks, but it can also help you transform crumbling slopes into tidy, usable terraces, perfect for your favourite plants, a grassy area, or a cosy patio.

Retaining walls can also be used to build beautiful squares or rectangular raised garden beds. Imagine rows of colourful flowers or a lush vegie garden, all neatly arranged and easy to access. You’ll look like a landscaping pro!

Related: How to erect a raised garden bed with Retain-iT

Retaining walls can be built from concrete retaining wall blocks, gabions, natural stone or sleepers. We love sleepers because they’re easy to get hold of, super budget-friendly and naturally gorgeous.

What are retaining wall sleepers?

Retaining wall sleepers are large, solid pieces of timber, usually rectangular in shape, used to build, yes, you guessed it, retaining walls! They’re typically made from treated pine or hardwood and are designed to withstand the weather and last for years.

What are retaining wall posts?

Retaining wall posts are the sturdy spine of your retaining wall’s design. To put it simply, they’re the vertical support structures that anchor and stabilise it. They can be made from timber, steel, or concrete and are buried into the ground, preventing your retaining wall from collapsing or leaning as the soil pushes on it.

Our Retain-iT systems are made from mighty galvanised steel, so they’re an awesome, durable choice.

What can I put between retaining wall posts?

You can fill the space between retaining wall posts with anything from classic timber sleepers to modern concrete panels or gabions filled with rocks or stones.

Do I need to use concrete to secure retaining wall posts?

For tall vertical retaining walls (over 2-3 sleepers or panels high) or ones that are holding in a lot of soil, concreting your posts in place is a must. Pour the concrete in one post at a time after you’ve dug your hole and put your post in place.

If you’re creating smaller walls for low garden beds or a sandpit, you can use our Retain-iT Heavy Duty Retaining Stakes. Simply hammer them into the ground, then screw them to your sleeper. Job done!

What can I use as retaining wall sleepers?

You can take your pick when it comes to choosing DIY retaining wall sleepers:

  • Treated pine – Kind on the wallet and easy to get, it’s a popular choice for timber sleepers. Resistant to rot, decay and pesky termites.
  • Hardwood – Some of the best are oak, jarrah, or red gum. Hardwoods are strong, beautiful, and more durable than pine but can be exxy.
  • Recycled timber – Super eco-friendly and can add character and uniqueness to your wall. Just make sure it’s treated for outdoor use.
  • Composite materials – Made from a mixture of recycled wood and plastic. They’re hardy, easy to maintain and resistant to rot and insects.
  • Railway sleepers – Usually made from hardwood or treated softwood. They’re perfect for a rustic look, but they do need a lot of love.

What size sleepers do I need for a retaining wall?

The most common sleeper sizes are 50mm or 75mm thick. 70mm is stronger and will last longer! Length-wise, 1400mm is a good standard, but you can cut to a size that suits your outdoor project.

Our Retain-iT 75mm durable retaining wall systems suit timber sleepers that are 75mm wide. For 50mm wide sleepers, use our Retain-iT 50mm system.

Do Retain-iT retaining walls interlock?

Nope, Retain-iT retaining walls don’t interlock because they don’t need to! You simply drop in your sleeper for a strong, long-lasting, and beautiful natural barrier.

How can I build a retaining wall with Retain-It?

Building a retaining wall with Retain-iT is as easy as ‘prepare, secure and drop in your sleepers’! It’s designed so even garden beginners can give it a go.

Here’s a more detailed breakdown of each step of your retaining wall project:

Step 1: Plan and prep

Measure the area of your DIY retaining wall and determine the number of posts you’ll need, including nifty joiner and corner posts.

If your retaining wall is longer than 2.4 metres, a joiner post will do instead of an extra-long sleeper. Our Retain-iT retaining walls go 4 sleepers high (800mm).

Step 2: Mark and dig

Level the area, then mark out where your posts will be. Dig holes for each post, ensuring a snug fit. A 200mm diameter is plenty. For stability, posts should be roughly halfway below the ground.

Step 3: Position and concrete

Grab your first two posts and pop them into two adjacent holes. Next, drop in one of your sleepers to make sure it aligns. We recommend two pairs of hands. Use a spirit level and string to ensure straight walls!

Once everything is in line, pour in the water and concrete to each post hole. Repeat until your wall is built!

Retain-iT or regret it!

It really is that easy with Jack by your side. So, forget concrete blocks. Retain-iT or regret it! With your retaining walls erected, your outdoor spaces will be the envy of the neighbourhood. And they should last 20 years or more!