How to secure hardwood steps on a slope?

Jaden

Hello,

I am installing hardwood landing pads on the slope of my front garden. I still need to install 1-2 risers to finish it off.

The Blue Gum hardwood is 75mm x 125mm.

The width of the steps is 800mm and depth into the slope is 475mm.

So far I have the frame of each step screwed together with 125mm Stainless batten screws x2 for each arm. Also a screwed in metal stake on each inside corner to hold the frame in place.

I was told that rebar through the wood into the soil would create moisture and increase instances of rot inside the wood, which is why I have avoided that method.

Looking to keep the outside clean looking without brackets or visible stakes. So my only option is to secure from the inside frame.

I may install another horizontal wooden brace towards the rear end of each step to stop the wood bowing outwards overtime, if necessary.

Looking to also create a buffer between the wooden steps and soil.

To finish off the steps, is crushed rock a good option to fill in the cavity? Looking to use crusher dust and a paver to finish the top layer of each step.

Any help with braket and screw selection would be amazing, and any other ideas to secure each step better.

Thank you,

Kind regards

MitchellMc

Hi @Jaden,

You’re actually on the right track with how you’ve framed them up. The 75 x 125 Blue Gum is solid material, and using stainless batten screws with internal stakes is a good start.

Where I’d improve it is exactly where you’re already thinking. You need to tie the rear of the sides together. Over time, soil pressure and foot traffic will try to push the sides outward. Adding another horizontal timber brace across the back of each step will stiffen the frame significantly. Alternatively, you could drive additional star pickets at the rear corners (on the inside so they’re hidden), or even screw the rear of the step into the riser above.

Regarding rebar through the timber: you were given reasonable advice. While rebar is common in landscaping, driving steel directly through hardwood into soil does create a pathway for moisture and can accelerate internal rot over time. Since you want a clean look without exposed hardware, keeping fixings internal is the better approach.

I would strongly recommend coating any timber that will be in contact with soil in a bitumen-based paint. Even though Blue Gum is durable, constant soil contact will eventually break anything down. A couple of heavy coats on the buried faces and end grain will extend the life considerably.

As for filling the cavities, crushed rock is a good option. It provides drainage and reduces water sitting against the timber. A compacted crushed rock base with crusher dust on top will work well. If you’re finishing the top layer with a paver, make sure the base is well compacted so the paver doesn’t settle unevenly over time.

Bracket-wise, since you want everything hidden, heavy-duty galvanised angle brackets on the inside corners (fixed with stainless screws) are fine. Otherwise, structural timber screws (like 100–150mm bugle batten screws) through the braces into the sides will give plenty of strength without visible hardware.

Overall, you’re close. Just stiffen the rear, protect the timber where it touches soil, and ensure good drainage behind the steps. That’ll keep them solid for years.

Please let me know if you have any questions.

Mitchell