We Chose Strawbale Construction but the Inner Walls are Made of Paper.
We love our strawbale house, it’s so well insulated our electric bill runs about $30.00 per month, our propane about $15.00 per month, we heat with the smallest wood stove we could find, cool with flow through ventilation and we live in the Chihuahua high desert. The temperature range can be extreme from the minus to over one hundred, but the house takes it all in stride. I have another article on the main building of the house.
Strawbales take up too much floor space when used as interior walls and I don’t care for working with wood. Besides, wood doesn’t weather well in the desert, it’s expensive, plus we’ve always tried to be environmentally conscious and recycle as much as possible. That’s where the papercrete walls came into being.
Papercrete, in various forms and for various purposes, has been used in the southern New Mexico for a few years and I used it as the core for property walls and other similar projects. I looked at the formulas that others were using and decided that, for what I wanted to do, none of them would be useable. Most papercrete is simply paper, water and portland cement. Some people had added sand for extra strength, fly ash to make the mix set harder or dirt in place of cement for a more earth-friendly, adobe like substance. The cement portions were too little for the sheer strength I wanted so I upped it to ten percent and added clay at five percent. Most others were making blocks, the same as with adobe construction, but it seemed that you ended up doing too many processes, pouring the blocks, drying them, turning them to dry the other side and then building the wall. I made forms and poured the walls in one operation. I used 1/4” horizontal and vertical rebar on two foot centers with chicken wire stretched over the rebar in the center of the wall(s). After two days, the forms were taken off and the wall was allowed to dry in place. I experimented with the walls around the perimeter of the property to find what worked best.
After the walls dried sufficiently, it took about five days so I worked on other walls or projects, and then painted them. I used regular interior latex paint, one gallon of paint mixed in five gallons of water or a five to one mix. I painted on a coat, which was soaked up like on a sponge and another the next day. It took five coats before the paint began to dry on the surface instead of being sucked into the wall. I let it dry for two days and finished with a coat of “full strength” regular latex paint. The walls are hard as sheet rock. I had to cut a hole for access to a cabinet and the paint had soaked clear into the center of the wall from both sides.
The final walls are about five inches thick instead of the twenty four inches they would be if strawbale. The interior walls don’t have as much insulation value as the strawbale but they don’t need it. They’re almost indestructible, but workable with the right tools.
I built a storage room and made it with papercrete, fibercrete or adobecrete, whatever you want to call it, and it doesn’t have the insulation factor of the strawbale construction. I doubt it would even if it was as thick. Plaster goes on much easier with less muscle power if a small amount of paper is added to the batch, and it’s easier on the tools too.
I’m very satisfied with the end product and wouldn’t hesitate to use papercrete as interior walls again.
The complete technique will be posted on www.larryRmiller.com as soon as I get the time.
Pictures of the interior and exterior can be seen on www.larryRmiller.com and www.adventureman1.com and as soon as the search engines find it, on nmstrawbalehouse4sale.com