What good insulation besides perlite or pumice?

Hello, I am starting to plan my home build, and we plan to install earthen floors.

I have seen tons of videos on this, and it seems people tend to use perlite or pumice as the insulation layer.

I live in NE Alabama, and neither of those seems to be readily available in bulk.  Does anyone else have other suggestions on what type of natural insulation could be used that is readily available in bulk in the SE United states?

Are you using a water/vapor/radon barrier under the house?
Do you plan on using any insulation along the foundation wall?
Will your earthen floor be 12inch above the the ground level or will it be 24inches above the ground level?


You don't actually need the insulation under the floor if you add some on the outside of the foundation wall, similar to slab on grade.

S Bengi wrote:Are you using a water/vapor/radon barrier under the house?
Do you plan on using any insulation along the foundation wall?
Will your earthen floor be 12inch above the the ground level or will it be 24inches above the ground level?

I am unsure how high it would be compared to the ground level, as a large chunk of the house would be underground/bermed.

And since a large part of it is bermed, I would not have foundation insulation exactly, but insulation between the berm and the walls/foundation.

And yes I would be using vapor barriers (probably billboard vinyls taped together)

Apparently bulk pumice comes from Georgia, so some investigation might uncover a reasonable vendor.

https://www.earthbagbuilding.com/images/plans/solar-pit-house-plan.jpg


Assuming you will be building a bermed structure vaguely similar to this, (maybe even with a green roof).
With the insulation on the outside, a vapor barrier (esp if paired with radiant floor heating) you don't need insulation under the floor.

Burl Smith wrote:Apparently bulk pumice comes from Georgia, so some investigation might uncover a reasonable vendor.

Oh, very nice. I'll look into that, thank you!

S Bengi wrote:https://www.earthbagbuilding.com/images/plans/solar-pit-house-plan.jpg


Assuming you will be building a bermed structure vaguely similar to this, (maybe even with a green roof).
With the insulation on the outside, a vapor barrier (esp if paired with radiant floor heating) you don't need insulation under the floor.

Awesome, thanks for this :) That is quite helpful.

Rice hulls

Concrete with shredded polystyrene foam

Aircrete using oil control shampoo as the foaming agent.

Now that you mentioned that your house will be underground/earth bermed. Here is a cool floorplan that you might take some cues from.
https://www.earthbagbuilding.com/images/plans/solar-pit-house-plan.jpg


I would love to see what your actual floor plan looks like.