Could one mix a 70/30 sand clay mix with rice hulls to provide insulation and not degrade the structural integrity of a building?
Rice hulls are supposed to be very good at insulating, but this is primarily because of the all of the trapped air that occurs when they are confined to a bag and plastered over. I’m afraid that if they are mixed with soil, the primary benefit would be diminished considerably because the soil would fill the voids around the hulls, and provide a solid with more the characteristics of thermal mass. It is like the straw in cob or adobe doesn’t really provide much worthwhile insulation. You would be better off using the hulls themselves and then plastering both sides with a stiff plaster with mesh imbedded to create a kind of “structural insulated panel”. Other natural insulating materials of mineral origin are crushed volcanic rock and perlite, if either of these are available in your locality. Q: I am going to build an addition to my main home. I am using earthbags to build the walls. I am going to build a rubble trench. The walls will be load bearing. The addition will be round with a m
