ᐅ Gabion walls with basalt filling – Rust issues?

Hello everyone,

We still need to install a fall protection system for our L-shaped retaining wall. For now, there is a temporary wooden structure and a fence, but we would like to find a long-term solution that looks good without costing too much.
We were thinking of using a gabion placed behind the L-shaped blocks.
We planned to fill the gabions with basalt crushed stone. However, a friend mentioned that this might cause the gabions to rust.
I did some research online, and it seems that basalt, because it contains iron, can actually cause metal—even if it’s treated against rust—to corrode when in contact with it.
Does anyone here have experience with this?

Best regards,
Christoph

Last week, I looked at some gabions at a supplier, and they were filled with different types of stones. One cage was rusty, specifically where the brown spots on the gray-brown stones touched the gabion. That surprised me as well.

Regards,
Sabine

Do not use basalt, it rusts...

Snowy36 schrieb:

Don’t use basalt, it rusts...

I think that’s the key point! It’s not the galvanized steel of the gabion that rusts, but the iron inclusions in the basalt. Use granite instead; it looks elegant, costs about the same, and nothing will happen!

Keep in mind that gabions can act as a supplementary summer heat source in your garden. They store solar heat effectively and help keep your garden warmer. If you have enough space, consider creating a hedge with a simple fence inside—such as beech. If space is limited, I would avoid disrupting the microclimate altogether.

Thank you for your suggestions and opinions. We had a landscaper here today, and it looks like we will be installing a double wire mesh fence in anthracite, mounted on the L-shaped concrete blocks.