Foundation concerns

I’m considering building an adobe near Taos, New Mexico, and I’ve been looking into my options for a foundation. Rubble trench seems like a decent option, but I have some concerns. I keep reading that you’re supposed to line your trench with garden fabric, but regardless, it seems like dirt would eventually find its way in and cause major drainage problems. Especially in the desert. My other concern is the French drain. It doesn’t seem like it would be able to hold up very well under a bunch of weight.. Does anyone on the forum happen to have a house on a rubble trench? Just curious to see if any issues have come up. Thanks!

Hi Josh!   One person I have followed here on the forums who I have particularly enjoyed watching his work is Daniel Ray balecob-home-earthbag-foundation-building

A few others I found that may also have some information for you:
rubble-trench-foundations

Kelly Hart's FAQ on foundations:
foundation

I'm sure someone else with more experience in this area will come along shortly, till then a little reading. :)

Seemed like, ahem, a well-founded concern... if you are looking to maximize longevity rather than minimize cost.

Garden fabric is... affordable.

Geotextile is much less affordable, but much more everything else.. I bet it would make a dandy substitute for the discerning foundation-builder.

I built a cob shed using a rubble trench foundation. The trench was lined garden fabric. The French drain in directly under the exterior wall. In retrospect, I would have offset the French drain just outside the wall to put my mind at ease that it wasn't crushed. I would have also spent the extra money for the perforated pipe with a sock.

Here's a link to my blog post about it.

Fourish years on on the foundation is stable and there aren't any water issues apart from water will sometimes wick up the exterior plaster because I didn't build an appropriate stem wall with a moisture break.

I think the biggest thing is to landscape your site so that water drains away from/around your foundation. The rubble trench is more of a last defense.