ᐅ Insulating a wood-based floor slab with straw

Currently, the idea is to insulate like a cavity insulation between rafters using straw bales, which are naturally highly compacted. What seems simpler to me with the roof is still somewhat uncertain when it comes to the floor slab.

manohara schrieb:

What is the plan?
Will the straw simply be "poured in," or are there any preparatory processes it goes through?

Filling it untreated feels too risky to me (just a gut feeling).
I think it needs some kind of fire protection and compaction.

Of course, such preparatory processes are necessary, and this brings us back to the same problem.
Meeting today’s required building standards plus—and this is the much bigger part—fulfilling our own expectations is often hardly possible with simple building materials, unless they are properly prepared, which usually means it is no longer environmentally friendly.
Therefore, the question of ecology and sustainability is extremely complex to answer.
In the past, many things were built this way and still are in some countries. However, people there live quite Spartan or even poor out of necessity, and ecology is a foreign concept. They simply use what is freely available, and if they are cold, they put on a coat or throw a piece of wood on the stove.
I find the approach fundamentally interesting, but I would not like the result.

I'll suggest using seagrass as insulation. It obviously needs to be applied in a sufficiently thick layer.

If the straw bales are to be used as they come from the field, there needs to be a plan for how to fill the gaps that "remain." (As far as I know, gaps in insulation significantly weaken the entire insulation considerably.)
... and these bales are not fire-retardant treated.

In the roof, it might be possible to blow in straw, similar to wood fibers used in insulation between rafters.
For solid wood exterior walls, only panels glued onto the wood would be feasible.
The floor slab really makes me uneasy. Moisture, animals, and so on. Then there's the structural aspect—reinforcement probably can't be laid or connected within straw.

The foundation slab would be constructed in the same way as the ceiling structure. Thus, no load would be placed on the straw.