How to build garden retaining beds?

[Cherry]

This is a follow on from a similar quaestion regarding extending a brick retaining wall. My husband decided to use gal steel to create the base. Then he is planning on screwing corten over the top of it including the existing brick rendered wall. Basically we are trying to fix area as cheaply as possible as quote for re-doing all in bricks was $20,000.

QUESTION is: can we use cemet sheeting on the inside to support the soil and take some of the weight of the corten sheets?

I am concerned they will rot with the moisture from soil. If so, any alternative cheap material suggestions welcome.

Before gal steel frame added

[JacobZ]

Hi @Cherry,

Thank you for your question about your garden bed.

I'm not aware of a fibre cement product that would be both strong enough and will resist issues with moisture in this application.

The best thing I can think of is 50mm sleepers attached to the back of the steel frame. These are treated for in-ground use, are reasonably priced, and are decently thick to resist the force of the soil pushing on them.

They could be attached to the steel frame with Zenith 12G x 65mm Galvanised Hex Head Metal Screws.

Allow me to tag @Dave-1, @Noyade and @Nailbag to see if they have any ideas.

Let me know if you have any further questions.

Jacob

[Dave-1]

Evening @Cherry 

Mmmm right up to about the time I saw the prices for concrete sheeting I was thinking along the same lines as you I wouldnt be using anything under 12mm really as you want something solid to hold the soil and considering the space between the top rail and bottom rail isnt too hight I would have said yep. Price wise tho... Woooooo So my backup option is wondering how much the core10 steel is? If its cheaper or the same then why not use it on the inside as well? You will need a bottom rail the same width as the top but really it should hold the soil.

Looking at the pictures, what did you decide to use for the top plate of the garden bed?

Dave

[Nailbag]

Hi @Cherry 

I agree with @JacobZ that the most structural and cheapest solution would be to use 50mm treated pine sleepers. 2.4m are only about $20. I build a raised veggie garden using these and made corner panels out of coreten. I also wrapped a couple steps to keep with the design theme.

Nailbag