Mikey Sklar talks about using the wall and ceiling sprayers on his Battery dome. His approach goes beyond just papercrete domes. This is a thin shell structure with an insulated core. Very economical to build and strong. Mikey sprays Papercrete that is his special blend with prickly pear cactus juice and latex paint for strength and weather resistance. He is a great inventor constantly looking for ways to turn inexpensive things into useful structures.
Thank you Mikey for sharing your research.