Hi Frank,
Welcome to the group. There are several people here that are in active projects, and a couple of thousand that at least think about papercrete while reading the posts. Any questions usually get several answers, and often most of them agree with each other. : )
I'm using a trash pump, supposedly rated 1.5" particle, but in reality it only passes things smaller than 3/4", and it clogs with shredded plastic that is mixed in with the paper I am using. It comes in a bale, and they aren't too careful to make sure it is all paper. When credit cards or clumps of other shredded plastic hit the pump, flow stops and I have to disassemble the pump which involves ten bolts and nuts, and then three screws which go into plastic and are starting to strip as plastic will after multiple uses. A good pump like a friend of mine has comes apart with no tools, but almost never clogs since it only has two vanes on the impeller, and will pass rocks up to 1.5 inches. His 4" pump cost around $1,000US on ebay including shipping, and would have been three times that much if he bought it retail. I paid about $350 new for mine at a local tool store, and wish I had educated myself better before buying. Even though I try hard to keep trash out of the mix, I still end up doing r&r of the pump after every couple of loads, four times yesterday. It would be worth the extra money to avoid that. Papercrete could be a one woman job with the right pump and slip forms. Actually there are several on this list who are doing papercrete pretty much solo with occasional help.
Borax that is used in laundry works well in papercrete. It comes in 30 pound bags at a commercial laundry supply store and ten pounds into a large mixer seems to do the trick. Besides killing that smolder it repels insects and mold. I watched a millipede crawl up onto some wet mix and in a few seconds it popped apart, like an internal explosion that separated its exoskeleton. I'm glad borax doesn't have ill effects on humans unless you powder it and breath the dust or purposely eat large amounts of it. I managed to start a smolder with a welder, on a piece of dried paper pulp that was in contact with the metal being welded. I thought I put it out but later smelled smoke and had to go back and douse it again. It burns very slowly and unless you have a whole lot of ventilation the smoke detector will alert you, so I'm not afraid of being trapped in a burning house, like I would be if I lived in a stick box. People who put dirt in their papercrete say the added strength and fire proofing is worth the added weight and loss of insulation factor.
You should take take the time to browse the archives, there is a lot of great information there. The photo section is great, Doris and Ron's project is about to come to the end, Judith has walls up 7 feet or so and almost ready for vigas and a pc roof. I'm slip forming around a geodesic armature, 12 inches thick.
The compression strength of papercrete is nowhere near concrete, but the right mix could support a lot of weight. For two stories I think I would want thick bottom walls tapered to maybe a foot thick at the top like they did adobe missions in the southwest. Then maybe vigas from a center stairwell support wall to the outside walls. My dome is 17' 6" D and the pc should be self supporting at 12" thick since it's a compound curve and mostly in compression. Once I remove the frame and supports I'll pick up an extra bit of floor space and the diameter will end up 18' or 254 square feet with an additional 50 sq foot loft bedroom. It has hydronic tubes in the slab and I'll attach a solar collector to heat the water in a storage tank for night time warming. Right now it's 71 and I'm feeling a bit warm, they have promised a breeze and clouds this afternoon. Probably won't get over 75 today. Just the thermal mass of the slab is enough right now, I'll get the solar boost going before it gets to be winter.
How large of a casa are you planning? Are you going cubic or ranch style? Solar? We need details!
spaceman
Frank wrote:
Just found your group. I am starting a project and experimenting with my recently upgraded mixer which is a work in progress. I discovered PC late in life but I believe it has great potential. I am looking for Trash Pump as that seems to me to be one way to reduce the labor factor. I don't want to re-invent the wheel and many of you have more experiance than me. I want to build a 2 story casa and believe that this should be possible with PC. My major concerns are that PC will smolder to powder if ignited (a work pad that I poured was ignited by molten steel from a cutting torch and turned to dust)(I am experimenting with boric acid to deal with this problem.)and that stacking block 20ft high and puting a roof load on it will cause the the bottom blocks to compress excessivly. I am hopeing that someone in here knows a good engineer. I understand that the UofA engineering school is doing some work on PC and wonder if any of that data is available? I've been to L ivinginpaper.com, and have seen Jack Husted's papercrete house in Eagar,AZ(it beautifull} I look forward to getting to know you and feel free to ask question's and make comments. I am located in Springervklle,AZ FiXeMQIcK
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