Earthen floor & radiant heat in reefer T-bar floor

I'm considering putting an earthen floor (sealed with linseed oil) in my insulated shipping containers (non-working reefers) which have aluminum T-bar flooring, and embedding hydronic radiant heating in the earthen floor.  Any advice on making this work?

There are lots of factors to consider.  Should I keep the containers' existing floor drain holes open?  Should the earthen floor be flush with the tops of the T-bars, or cover them with 1/2" or so?  Can I lay the bottom layer as dry sand/silt and wet & compact it after laying it, to make it easy to insert it between the T-bars?

The 2 containers will serve respectively as a personal library/living room/storage & workshop, so my main motivations for an installing earthen floor are:  I want to be able to sweep the floor (T-bars are hard to sweep/vacuum), heat/cool silently (any noise echoes loudly), and save money on flooring (plywood & concrete cost more).

I reckon you would be better to install the plywood floor with a suitable surface to sweep.
In my experience thin earthen floors crack too easily.
By the way what are "(non-working reefers) "? Why use such a word?
Is it a refridgerated unit?
I will encourage you to save a bit longer for a better outcome.

Insulated shipping containers with defunct refrigeration equipment.

I think an earthen floor would need to be several inches thick over T-bar projections or it would quickly crack at each T-bar, and start deteriorating from there. I can appreciate the acoustic motivation as well as the underfloor heating possibilities, but I don't think the material is practical for a finished floor in this case. You might fill up to the T-bar tops with compacted earth and embedded hydronic tubing, and then put plywood or other wood flooring over that for a finished floor. In utilitarian spaces, I could even see pallet wood flooring (sanded for a smooth surface) if labor is cheap and money is short. Otherwise, you can get a solid if uninspiring floor with medium grade plywood for maybe $1000 more or less for two 40' containers. Earthen fill compacted under that will help damp the acoustics.

I agree with Glenn.

If it were me, I would use sand to fill in the slots as it will shift as the aluminum expands and contracts. Then whatever you can get that meets your price/performance requirements. I would probably do 2x4 word bricks because I have access to framing lumber off cuts.

John C Daley wrote:By the way what are "(non-working reefers) "? Why use such a word?
Is it a refridgerated unit?

Yes, they are refrigerated shipping containers (often called "reefers" here), but the refrigeration units no longer work.