Papercrete by Judith

About 4 years ago I bought a beautiful piece of land on a mesa in northern New Mexico and started researching alternative building materials. I begged borrowed and bought every book and video I could find on all the newest methods and materials.

I had a certain criteria for what would be acceptable to me. First of all it had to be environmentally friendly through the use of natural materials and/or recycling. It also had to be energy efficient and really inexpensive, easy to make of readily available components, lightweight and able to be handled by a person working alone. Along with all this it had to have a beautiful, comfortable, nurturing, and aesthetically appealing end result.

I was originally drawn to straw bale construction. Loved the idea of having walls made of such a beautiful natural material and the finished product was so substantial with very thick walls. However, I had attempted to build a wall of bales a few years earlier and knew that I would have a hard time handling them myself. Besides that the price of bales had just jumped and I didn't have the cash.

My second choice would have been cob, a mixture of soil with a high clay content, sand and straw. Buildings made of cob are charming, warm, inviting and uniquely personal. They have rounded corners, nooks and a delightful use of space. The materials are all around us, mostly free for the taking. Seemed like the perfect fit.......until I decided to mix up a batch one day. This is definitely a project for the person who has plenty of friends with a lot of energy and time on their hands. I put all the materials on a tarp as instructed and then began to stomp them with bare feet as I turned around, lifting the tarp to redistribute the mix. After about one minute I was exhausted, dirty and discouraged. I managed to make two large blocks of cob which soon hardened into almost indestructible little loaves. THE HAND SCULPTED HOUSE by Ianto Evans, Michael Smith, and Linda Smiley is still one of my all time favorite books, but I knew I would never live in a cob house.

I read up on Earthships and loved the concept of living off the grid, collecting rainwater, using and reusing it up to five times, loved the way they bermed into the earth, but realized that pounding all that soil into those tires would be the death of me. So I gave up on that idea.

I looked into using earthbags filled with sand and even sent for 2000 bags. I did end up using them for my foundation (filled with large chunks of pumice) but felt that they didn't offer the R-value (insulation) I thought would be necessary for passive solar living. And besides that I personally do not care for the dome shape
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Just when I was getting really discouraged I had an email from Charmaine Taylor of Papercrete.com, suggesting I look into papercrete. I had borrowed and bought just about every DVD and video there is on natural building from her very well stocked online store (WWW.DIRTCHEAPBUILDER.COM). She knew my criteria and suggested I look into papercrete. I ordered all the info she had and as soon as I watched the first video I knew I had found what I was looking for.

I ordered an instructional DVD from www.livinginpaper.com. I didn't even take the usual step of mixing up a small batch to experiment. As soon as my mixer was ready I started making papercrete and have been happily doing it ever since.

Papercrete is a mixture of recycled paper and portland cement. An aggregate such as sand or pumice can be added to increase volume and mineral content (for fire retardant and insect resistance) is generally added to the mix.

INGREDIENTS:

PAPER

Just about any kind of paper can be used including newspapers (my current favorite), office paper, cardboard, brown paper bags, even junk mail, you name it. Depending on the kind of paper and mixer you use you can either soak the paper for a few hours or overnight or just throw it in like I do.

CEMENT

Cement (or soil with a high clay content) is what binds the whole thing together. I use a 60/40 mixture of portland cement and fly ash, which is a byproduct of the coal fired power plant in the Four Corners area of New Mexico. When coal is burned the fly ash goes up the smokestack. In order to keep it from polluting the air it is caught in screens and recycled.

I use a very small amount of cement in my mixture. The idea is to use as much recycled material as possible and keep the carbon footprint small. Cement production puts a lot of CO2 into the atmosphere so I want to use as little as I can and still come out with a finished product that is as strong as it can be. The more cement and aggregate you use the less shrinkage you will have. I played around with my formula, and still do, with the goal of having the strongest, lightest, most shrink-free result. Adding the pumice or perlite will increase the mineral content thereby reducing the flammability and shrinkage.

AGGREGATE

Adding an aggregate to the mix will increase its thermal mass, reduce shrinkage, and add to its fire and insect resistance.
I started out using sand because that's what was called for in my original mix recipe. But one day when I was at the gravel yard I noticed a big pile of pumice at the back of the yard. I made a snap decision to go for the pumice in stead of sand and found that it improved the mix. It is a mineral that is a result of volcanic activity. It's lightweight and traps air, making it an excellent insulator. Pumice is about the same price as sand but it is a lot lighter and adds R value (insulation) to the final product. People are experimenting with different things in place of sand, such as ground glass.
I will be switching to perlite when my pumice supply runs out. It is also a volcanic mineral but is more readily available for me now that the pumice plant has gone out of business.

The first batch I made had high clay soil in it. It came out fine but took a long time to cure so I decided to use cement. I'm seriously considering using soil in my next building project. it will certainly save me some money but my intent is to be more kind to the planet.

Paper is basically cellulose, a natural polymer, a long chain of linked sugar molecules.These long chains bundle together, the fibers forming a matrix that looks like a big tangled web. Coating these intermingled tangled fibers with cement (or another binder such as clay) creates a hard shell around each individual fiber, giving papercrete its great strength. After the water leaches out what you have left is cellulose fibers encased in cement with air trapped as well. This makes for a very strong finished product that is light weight.

SOME OTHER PLUSES

Along with being strong and light papercrete also has a great R value. Depending on the formula it has tested to be between 2 and 3 per inch. That means that a one foot thick wall would have an R value of up to 36. To compare? You've probably seen rolls of fiberglass insulation at the home stores labeled R-11 or R-19. That is there R value, their insulation rate. So you can see that papercrete offers more than the conventional insulation we're familiar with.

The insulation value of papercrete relates to its sound transmission quality. It is a terrific sound barrier.This was demonstrated to me while I was building my house. I had a phone installed but since I had no structure to put it in I bought a mailbox at Habitat and had the phone put in there. I figured it's dry and protected and just the right size and shape. The "phone booth" is about 10 feet from the wall of the house. Once that wall got to be above my head I could not hear that phone ring! (A friend shot the wall with his gun too and the bullet didn't go through. More testing on that to come).

Papercrete, because of its high mineral content is fire retardent and insect and rodent resistant. I did a flame test with a block of my papercrete. I held a blow torch one inch from the surface of the block for a full five minutes. The block did not get hot. I could press my hand to the back of the block and felt no heat transfer. The area where the flame hit glowed red and was turned to ash, but there was no ignition and I could put my finger directly on the ashen area right after the flame was turned off. I watched the block for several hours to see if the ash spread and it did not. I believe Barry Fuller at www.livinginpaper.com has test results for sale on his website if anyone would like more scientific proof.

Another beneficial quality of papercrete is that is rather flexible. That along with its light weight make it a perfect material for building in earthquake prone areas.

Papercrete is easy to cut and sculpt. An entire wall can be erected and allowed to cure completely. Later you can come in with a chain saw or reciprocating saw and cut out your doors and windows, carve niches for shelves, or create imaginative features. The higher the mineral content the more chains/blades you go through so keep that in mind when you are planning your project.

And as I've already emphasized, papercrete is something I can do myself. I can handle all the ingredients that go into the mix. I can drive the truck around to mix it. I can make the blocks and lay them up into walls or pour the walls in place. Of course it's always easier when you have someone to get things for you or hand up a bucket of slurry when you're up near the top of the wall. But it is possible (I didn't say easy) for a person of not great strength to get something built out of papercrete. As I add to this lense I'll be sure to include a module on how to work alone using the laws of physics such as gravity and leverage. I'll also share some tips about how I can do things by myself that are usually done by people working together.

I make my papercrete in a 200 gallon tow mixer so I'll share that info with you first and then explain how you can make smaller batches for different uses. I'll also include information on the different mixer styles and sizes. But for now here's my mix recipe and method.

As I said, I have a 200 gallon mixer. It's made of a stock tank mounted on and welded to the rear end of an old car. More about that in the MIXER module.

I start by measuring out my ingredients. Since cement is very heavy even in small amounts, I put it into two five gallon buckets. This equals a half of a 94 pound bag of portland cement. Even these are pretty heavy so you may want to divide it into smaller portions. I lay the buckets down on the lid of the mixer. Then I fill four more buckets with the pumice fines (the smallest grade of pumice, about the consistency of coarse sand) and set them next to the mixer. I use newspapers because they are easy to handle and measure. I take a stack about 22 inches high and set it next to or on top of the mixer.

Then I turn on the hose and while the water is filling the mixer I roll the buckets of cement on the mixer lid and the cement sifts into the mixer. I usually wear a mask while doing this as the cement puffs into the air a lot. The pressure of the water mixes and dissolves the cement.

When the cement is completely suspended in the water I start throwing the newspapers in. I don't tear or shred them up but I do try to separate them as much as possible and keep playing the hose over them as I add them to get them wet.

Then I pour the pumice fines right on top of everything. They float on top until the mixer starts moving.

When the the mixer is full. I start driving slowly around the block and the movement of the wheels turns the blade in the mixer. The paper is shredded and mulched in the water/cement mixture and the pumice is drawn down and blended in. I drive at about 5 mph most of the way around the block, speeding up to maybe 15 on the level straightaway. I only have to go about a mile and the mix is done. It looks like cooked oatmeal and if it's done just right it will easily flow out of the mixer into the form.

There are a lot of things you can do with papercrete, but if your goal is to construct a building you have basically two choices for forming the blocks. You can do a form for individual blocks which you would then lay up just as you would adobes, using the slurry as mortar. or you could do a slip form. I'll explain each of these now.

FORMS FOR INDIVIDUAL BLOCKS.
I make my forms of that composite decking material. It is more expensive but is environmentally friendly because it uses wasted materials. Another advantage is that it doesn't warp, a problem I have had in the past with wooden forms.

If you are using a tow mixer you must make the forms so that you can drive over them. My forms are made of 2 x 6 decking material 30 inches wide by 12 feet long. This is the perfect size to hold the contents of my 200 gallon mixer.

In the past I have left the form without interior divisions. I have poured all the slurry into the form, let it set for about 30 minutes, cut the blocks into the size I need with a garden edger or flat shovel, and pulled the form off. All of this is demonstrated very well in my 55 minute DVD THE MAKING OF PAPERCRETE available on my website www.papercretebyjudith.com.

The most recent blocks I've done have been in a custom made form. The basic dimensions are the same but I put divisions between the blocks. I have a slip form wall I've been working on and want to put these blocks on the top course where I won't have room to pour a bucket of slurry. There is already a beam at the top of the wall and the slip formed wall will have to fit under that beam and actually come right up to it and around the bottom of it. So I measured the thickness of the wall and put the dividers in the form at that distance apart. What I ended up with were blocks that are 30 inches long by 10 inches wide.

These dividers between blocks can be made out of scrap lumber you happen to have lying around or you can get creative and use anything you think will do the trick. Some day when I have the time I'm going to go to the big salvage yard in Albuquerque and see what I can find that might work as a form. I think something like store display shelves or.......well I won't really know until I see it but you get the idea.

You can leave these blocks to dry completely or use them in the green stage, before they have dried. In either case set them on end to allow more air circulation.

THE SLIP FORM METHOD

I have recently started using the slip form method and am planning to have that as my default forming method. The walls come out very uniform and smooth and the intermediate step of handling individual blocks is eliminated. There is a trade off though in that large amounts of wet slurry must be somehow moved from the mixer to the form.

The wall that I am currently working on already had posts at both ends of its 11 foot length. All I had to do was run a form on either side of the wall from post to post. I made the forms of plywood with reinforcement of 2x4s to keep it from bowing out. The forms are 1 foot high. I just screw them into the upright posts on each end, both sides of the wall to contain the slurry, pour the slurry, wait about 30 minutes until the water has leached out and the mix is firm, unscrew the forms and move them up to the top of the course I just poured. I have done 4 courses a day this way with no adverse effects. The top courses have not compressed the underneath ones, but I am not sure how many I could do without this happening. I am ready to start a new project and will document all of this to be included in a new DVD which will also be available on my website www.papercretebyjudith.com

I will be running workshops most weekends starting in April or May depending on the weather. The fee for 4 days including meals is $350. The schedule runs as follows:

Thursday late afternoon to evening - arrival, orientation, getting to know one another, cocktail hour, dinner, refreshments depending on the time.

Friday - out to the project to get started. We'll break for lunch and be back at the base camp in time for everyone to get cleaned up for dinner.

Saturday - more work on the current project with plenty of time for whatever the students want to learn.

Sunday - we can finish up what we have been working on, review, or take a break and see the local sights. We live in an astoundingly beautiful area and love to share it with visitors. Guests leave in the morning or afternoon.

I started a new project at the end or September and almost got the roof on before the cold weather hit so I will be finishing that up as well as starting another small building to be used as a bath house.

Come for a day or two if your schedule doesn't conform to the workshop schedule. I have a nice guest suite and will provide great meals

Fee is $90 per day.

We have plenty of room for camping in tents or campers. We have a nice guest room for those who need a real bed and bathroom nearby.
There is also a lovely B & B next door and the Abiquiu Inn is very nice. You will have to call for prices.

Plaza Blanca B & B by Dennis and Ann Harris (505) 685-4505

The Abiquiu Inn (505) 685-4378

Email me at williams_judith@hotmail.com (505) 685-0804

We are located about 50 miles north of Santa Fe. Those flying will come in to the Albuquerque airport and will need to rent a car. It takes about 2 hours to drive here. If you are driving you can Mapquest me by typing in the address, 82 County Road 158, Abiquiu NM 87510

www.papercrete.com
This is an amazing website with lots of great information about papercrete and an unbelievable online store for all your natural building books and DVDs.

www.livinginpaper.com
Barry Fuller's site provides everything you'd ever want to know about papercrete and more. He has been developing and testing papercrete for years and offers all his experience and knowledge here.

www.evesgarden.org
Eve's Garden is a Bed and Breakfast in Marathon TX. Clyde T. Curry built this amazingly beautiful sanctuary out of (you guessed it!) papercrete. There's a lot more than relaxing going on around this place. Take a look.