Rammed earth foundations

Hi all
I am new to this site and looking for some advice on rammed earth construction
I am currently involved in a project in Papua New Guinea, where the goal is to help the locals develop skills in building with rammed earth
Most of the sites are remote and we will be bringing formwork and some cement in but are trying to utilise as much local material without impacting on the integrity of the building
Looking to make the wall about 400mm thick
Thought was also to do a trench foundation under the external walls, that will be lined with plastic sheet with an slotted Ag pipe at the base to drain off any ground water
Plan to fill that with stone and rammed earth mix
Can anyone advise if this would be sufficient?

Also plan to have a raised timber floor in the houses, and like some advice about concerning the use of using square rammed earth piers to support the floor, they would only need to be 500-600mm high and 400mm square

Any advice would be really appreciated

All the best

Al

What have the locals been building with?
They usually have found out what works for the area.
I have experience with Rammed earth, it does not like moisture in the sense of being a foundation.
Why not use stones to bring the foundations above the ground level? Its been done for 1000's of yeras.

I have been living in rammed earth for about 25 years and love it, and also chose it for my personal house a couple of years ago. I agree with everything John says above. We use dry stone foundations, with or with out an RCC course above it and below the rammed earth. I like the simpler but thicker style of rammed earth, which does not use any cement. It's almost like cob into formwork.

But it would be great to use methods that are locally known, or only tweak them a little. I think I've seen wattle and daub in photos of PNG? Not sure about that though.

Thick earthen walls have a wonderful ability to even out the temperatures between day and night and even for a couple of months. Is the average temperature where you are often comfortable? This could make a condensation problem if you have a longish cold season followed suddenly by a warmer, more humid season.

Thanks John and Rebecca
Locals in PNG have never used rammed earth to build it will be a new thing for them
The mainly build there houses on stilts with enough room under them to easily walk under, not sue the origins of this, I don’t believe it is to do with flooding as they do not build where it flood, I think it has to do with security, probably again humans more than animals lol

Rebecca can you tell me what thickness of wall you recommend?
Also am I right in think that a foundation of rocks to up to ground level that is tamped down would be sufficient to then build the wall ontop?

They do have a bit of a wet season in places but it is usually the same temperature most of the year, hot and humid.
I was also considering using a type of sealer that I could spray on the wall to make them more water resistant, any suggestions.

The homes may be on stilts because of the heat.
In Queensland many homes were built on stilts so the wind can pass under and provide cooling.
In some communities they prevent vermin getting in

Papua New Guinea ranges from 80 to 160 inches of rainfall a year and relative humidity of 70% to 90%, this is a very moist place...