ᐅ Using Topsoil as a Base for a Terrace?

Hello,

I am planning to build a wooden deck soon and want to use leftover topsoil as the base. My plan is to simply compact the topsoil with a plate compactor and then place the deck on top. Is this feasible, or is topsoil unsuitable as a base material?

Topsoil cannot really be compacted. It contains many organic components that resist mechanical compaction.

Additionally, there is a risk that seeds present in the topsoil will germinate and then grow through the terrace (dandelions can definitely do this).

Precise digging is not recommended. I also planned to do this and had a pond excavated. I intended to use this topsoil for the terrace. We were advised against it. Topsoil is not a load-bearing subsoil.

Topsoil as the upper layer is highly unsuitable. Of course, it’s tempting since the soil is right there, and you might think you can just use it. I made this mistake years ago, and the topsoil simply couldn’t be compacted. Well, we ended up raising our terrace.

No, topsoil is not suitable for this. I used clay soil as the base layer, which compacts well. The top 20 cm (8 inches) was filled with basalt gravel. It is also important that the upper layer remains frost-free.

Under no circumstances should topsoil be used as the final layer. That will only cause problems. I applied crushed stone as the base layer on my property. This is the proper foundation for a terrace.