I'm prepping for the install of an Earthen Floor in my building. I have been planning on installing the tubing as well to heat the floor for hydronic radiant heating. I've received a couple unsettling accounts around the negative impact of hydronic heating systems in Earthen floors, including the following:
A local Natural Home builder experienced with Earthen Floor installation was sharing some insights about hydronic heated systems in earth floors and how they effect the oil finish.
He mentioned that when the earth heats up, the placidity factor of earth increases because of the linseed oil. He shared that the oil becomes tacky when heated to the point where he no longer turns on the floor heat because the floor surface gets too sticky and ruined his rugs.
I had not heard of this happening before, but seems worth investigating. I'm not sure if there is an additive that can be used in the linseed oil that helps it stay stable when heated? Might the addition of Portland cement, or lime into the Earthen Floor help with its properties when heated?
BTW, for my install I'm following the procedures and protocols for a, "compacted gravel (road base) subfloor", as outlined on pp. 109-112 in the book: "Earthen Floors - A Modern Approach to an Ancient Practice" by Sukita Reay Crimmel
And James Thomson Copyright 2014 by New Society Publishers. Though the system of the install is really tangential to the issue of how hydronic heating affects the finish surface of these types of floors.