How To: Papercrete

This is a great time for creating. Spring is near and outdoor projects beckon... I just finished with my experiment in papercrete brick creation and i'm really pleased with the results. Here go:

What is papercrete:

Basically, papercrete is concrete made with paper pulp mixed in with sand, earh, and cement. I'm not a big fan of using portland cement so papercrete is a really good adaptation to the recipe. I'm sure most of you have had some exposure to this, i just wanted to post my basic brick tutorial and some basic information about the craft.

Some of the benefits:

It's breathable and semi-permiable.... That means that it soaks up moisture like a sponge but it can evaporate out. When using strawbale, the ability for your walls to air dry after a storm is key.

Apparantly bricks made with papercrete can be produced for $1 per square foot, i'll agree with that. You might be able to get it cheaper.

It has many uses: stukko, plaster, casting (bricks, any molded object), pouring, etc.

It's really light. Cuts down on the amount of energy it takes to build something!

Materials:
Paper (any will do, but newspaper, magazine, and office paper are best [in that order])
Buckets
Mold making materials (wood, screws, drill, etc)
Drill and mixing "bit" (it's not really a bit, more of an attachment, there's a picture below with my drill and attachment)
Portland cement (do NOT get quickcrete... you need either portland cement or roman cement [clay-lime mix... hard to find at the store])
Sand (don't waste your money on Play Sand, get the cheapest you can find, the cheap stuff is actually courser and works better.)
Earth (anything will do, but i would assume that good clay earth would be best... dig a hole and at the bottom should be some clay... but just so you know, i used topsoil and had no problems)
Trowell (anything you can use to spread this and pack it into molds and whatnot)
Some form of strainer (a collander will work, but i made a strainder to put on top of my wheel barrow.

Pulp:
[list]
[*]Shread newspaper, office paper, magazine paper (for certain things it's actually best!), envelopes (remember to take out the plastic window if it has one), napkins, etc.
[*]Put that in a large pot and cover with water. you'll be able to get quite a lot of shreaded paper in, just keep pushing it down into the water. Fill the pot (i actually use a pressure cooker, which i feel works best and produces the least amount of mess) with water and begin to boil. Stir occasionally for about 15-30 minutes, or untill you totally can't read the newsprint and it's falling apart.
[*]pour into a bucket. Using a drill and a drill attachment used for mixing (i'll link a picture as soon as i can) blend the hell out of it untill it's the consistancy of cottage cheese.
[*]keep a lot of water in the mix for storage, this stuff lasts a while.
[/list:u]

I made much more than i will need for this project, here's a picture:


Making a mold:

You can really cast anything with papercrete, but, because i wanted to test out some different recipes, i made bricks. My bricks are larger than standard bricks at 4"x8"x3".

Here's the mold:


Mixing the papercrete:

There is no one right way to make papercrete!

Here are some common recipies taken from the site that i worked from to make it myself.... also, i made four bricks, I made one brick of each recipe to test it out.

[list]
[*]50% wet paper pulp/ 30% damp earth/ 10% dry sand/ 10% Portland cement/
[*]60% wet paper pulp/ 20% damp earth/ 15% dry sand/ 15% Portland cement/
[*]65% wet paper pulp/ 25% damp earth/ 10% Portland cement/
[*]70% wet paper pulp/ 15% damp earth/ 15% Portland cement/[/list:u]

The first will be hard and heavy and the last will be light and, i assume, weaker.... Still strong though. These recipes and my proceedure were adapted from http://www.hybridadobe.com/how_to.html

Put your paper pulp into a stainer of some kind.... get most of the water out. Here's my set up:


So, pick a recipe and put the ingredients in a bucket and mix well. Since i made relatively small amounts of each recipe, i measured in cups.... (5 cups paper pulp, 3 cups damp earth, 1 cup sand, 1 cup cement) It's good to establish a unit for your percentages instead of just guessing how much you're throwing in. The drill attachment really comes in handy here because the ingredients didn't all want to mix in well for otherwise and consistancy is key. I wish i had taken pictures at this point, but alas i didn't.

Pour it into whatever mold you have or however your going to use it making sure that if it's in a mold that it's packed in there well as it's not going to look right or be structurally sound if it's got pockets in it.....

Let it dry for a while.... overnight or something in a dry place... When you wake up, lift the mold and shake/press the bricks out. When i say overnight, i mean for something like a brick.... if your doing a large cast sculpture, it may take awhile before you should release the mold.... The bricks are certainly not dry at this point, so let them sit there for a while and dry. Place them on a pallet as soon as you can, or some form of surface where air can get to as much of the surface as possible, i used the mold to do this.



Again, only do that once they are hard enough not to bend or fall apart... use best judgement.

I got impatient and threw them over an electric radiator:



And that's pretty much it, you get a brick that weighs about 1/4 of what a normal brick does and you use FAR less cement.

Wow! That is pretty cool So can you make bricks and use them for landscaping?

What a great way to dispose of your shredder paper. I would experiment with natural dyes and add some colored rocks to make pavers.

I add fiberglass to all my concrete flatwork and it virtually eliminates cracking. I wonder if adding a little bit to the mix would strengthen them for use as pavers???

MJC wrote:
What a great way to dispose of your shredder paper. I would experiment with natural dyes and add some colored rocks to make pavers.

I add fiberglass to all my concrete flatwork and it virtually eliminates cracking. I wonder if adding a little bit to the mix would strengthen them for use as pavers???

Hi, Great site. I've been searching forever it seems for somewhere to discuss papercrete issues!

I don't know if papercrete would work very well for pavers or sidewalks ect. from what I've read it soaks up water really easy.

I do wonder how well cardboard would work for a filler? I produce vast amounts of it from my business. I think I'll try a little experimenting....I would think that the glue used in the process of making the cardboard layers would only add to the structural strength of the finished product ??

Also, has anyone had any luck in using an inexpensive waterproofer/repellent thats added to the mix?

I think the absolute best paper pulp would be something longer-staple.

For instance, there's a good article here on processing switch grass into raw, long-staple pulp:

http://www.cs.uiowa.edu/~jones/prairiepaper.html#Materials

It mentions in passing that oat straw has been used to make paper. 

A corded drill would help in this sort of pulp-making, of course, and might do better than a blender at leaving fibers whole, while still being less labor-intensive than a mallet, but I'm not 100% certain that a wide mixing blade would be intense enough for the very first stage of pulping, or that it could handle very long fibers.

Separately, I'm intrigued by what might result by introducing a kombucha culture into the fiber/sugar mix.  It might make for some good vegan "leather."

Edit:  Another thread mentioned Kenaf as a method of bioremediation for high selenium content, but I had never heard of that before.

Turns out, it's one of the best plants to use for paper.  The tops are also very good forage, apparently...better than alfalfa for some purposes.  Just thought I'd mention it.

My partner and I built a house out of tires and papercrete (a slurry made of pulped newspapers, clay and Portland cement) . We started with a free mobile home (12' by 55') and built two, 6' by 55' additions along the sides (we made the additions on a foundation of packed tires and poured 12" thick walls on top of the that foundation) and then peeled the mobile home sides off to open the whole home which is now 24' wide by 55' long. We have a greenhouse made of used sliding glass doors at the south facing end and the whole thing is covered by metal roofing from a scrap yard. We are about to make our own solar panels from parts on eBay and a wind turbine from PVC pipe. We are wondering if anyone else has done anything like this or is thinking about it. BTW, we are both women, 55 and 56 years old. http://www.builtfromtrash.com [/color]

i have a friend that does this get paper from a news paper place and buyes the broken bags of portland and lowes and home depot for 50cents i think has enoff to build a structure know

the cheap guy

IG-88 wrote:I do wonder how well cardboard would work for a filler? I produce vast amounts of it from my business. I think I'll try a little experimenting....I would think that the glue used in the process of making the cardboard layers would only add to the structural strength of the finished product ??

I have never used papercrete but it sounds interesting.
A quick search on Google found me quite a few references to using cardboard in papercrete.

The question I have about papercrete is how do you deal with moisture? I have found references to observatory domes made of paper (mache?) which were in use for decades but  how to deal with the weather when used open to the elements like that?  I am trying to figure out how to do a roof with recycled cardboard -light and strong- but the weather thing is worrisome. Odd to think they had this solved  over a hundred years ago but is such a problem now!

Depends on what 'kind' of water.

Think of it as Cob but not as fun to work with. But rubber gloves are a must as the concrete is caustic. Acts like cob if you drain off the mix. Can pour blocks, slip pour, cob...etc. Can also be sprayed but I haven't done that yet.

http://www.youtube.com/watch?v=twt1srsq_Hg

The paper fibers acts like millions of tiny rebar held together by cement. Block/mortar builds turn monolithic as they are the same material so it's super strong.

Don't want it sitting on the ground or have constant moisture. But it dries in a semi-expanded state so there is minimal swelling when it does get wet. Thick walls/roofs will can absorb rain (soaks in an inch or so) then it evaporates off.  Plan on playing with that to do a free standing evaporative cooling wall...

PC is great stuff. Started a PC building a few years back, got the foundation done but got side tracked after taking my PDC. Funny that.

These guys a all about the Papercrete...lots of info, specs, etc.

http://masongreenstar.com/

Yes well last summer we didnt get three days in a row without rain - a LOT of rain -  so  anything that allows water to " sink in an inch or so" isn't going to work.   I didn't  think cob is normally used as roofing material?

I know it is possible to deal with this  just not sure of the right way to go about it.  If I was going to use any cement  on the roof I would do a couple of layers of cement impregnated burlap because that's fast and easy but I don't want cement at all. I was wondering if some sort of lime concoction might work, or if I am going to have to bite the bullet and use a chemical finish of some sort.

Apparently one thing  they used to use  was a lot of linseed oil but not at all sure that would react to today's paper as it did to the paper they used.   I have worked some with paper mache but haven't looked to leave it anywhere it would get the full brunt of the weather.  It CAN mould even if you add stuff to the mix, and mould is a big no-no. So I am trying to find out how  other people keep it dry.  If they do.

Pam-
I was speaking of raw PC (no plaster) which is something most wouldn't do. There is a guy (lives in the desert) that made a small PC building for growing snails in. Keeps the inside at 90% humidity all raw PC inside and out and has no problems with structural integrity.

Once a lime plaster is on it's water proof and breathable. You don't want to put any non breathable finishes on.

PC is light weight too. Standard adobe block size are around 8 lbs. each.

Lime would more than likely work but you'd have to set them on pallets and wrap them in plastic for a month to slow cure.
This guy is making lime stabilized compressed earth blocks...really nice stuff.

http://www.institutotierraycal.org/

Thanks for trying to help, ape99,  but I DO want a waterproof face on the paper mix. Not on both sides, but definitely on the outside facing the weather. Most of the people doing papercrete as well as the people whose link you sent are working in a relatively dry or desert climate, totally different to what we have here, and what works there simply won't do here. You will note that any form of adobe is unlikely to be found outside relatively dry climates, even with lime plasters, unless with large overhangs to protect the adobe from the weather. We have snow load ..this year for probably about 7 months of the year and rain for at least another four. Something  which absorbs water will have little chance to evaporate it before it gets wet again until finally it would be soaked through, with still more rain coming.

The use of lime is of great interest but I would be very cautious about using any old soil with 15 or 20% clay with lime and expect it to form rock, my understanding is that there is a need for certain chemicals to be present for the reaction to take place. Certain types of clay/lime certainly work; Davidovits  maintains that is how much of the pyramids was built. But it seems to me that expecting any old clay/lime combination to work is like throwing a random combination of flour and eggs etc  together and expecting it to turn out a cake. In a DRY climate  there isn't the same sort of stress for the blocks to handle from the weather.

Please note I am not talking about walls here..even the people doing the stabilized earth block walls appear to use something else for the roof.  And again, they are in a very dry climate.  I am aware of the myriad options for walls and they are not in question.  I am attempting to find out what if anything people use or have tried to waterproof paper or cardboard to use as a roof, and I use the term waterproof intentionally.

Yeah you should put a water proof finish on PC...like a lime plaster.

You just want to avoid any vapor barriers (latex paint...etc).

Then any moisture that gets in there will be trapped and eventually lead to problems.

Again just treat it like cob...and cobs been used for 1000s in wet places.

Best of luck to you...

Thanks for the recipe!  I've been wanting to make building blocks by pouring paper-crete into my cardboard 12 pack beer boxes filled with empties. Think it will work?

The Christine house by Rural Studio used infil blocks made with various paper forms. http://bartlettyear1architecture.blogspot.com/2010/02/rural-studio-christine-papercrete-house.html
I like it.

I have a dome in my back-yard that looks like a cement igloo.  I originally took some 1/4 inch 20 foot steel rods, stuck one end into the ground and bent the other end down, stuck it in the dirt, then repeated the process with about 15 of these rods, leaving an opening to later have a door. ( several years later now... it still doesn't have a door. )

I originally coated it with plastic to use as a starter greenhouse.  It worked fine. The next year most of the plastic was in tatters... so I got some 1$ a yard cloth from Walmart and covered it with that.  It made a nice sleep in the back-yard tent for a few  months.  The problem with leaving a mostly free-standing tent in your back yard is that  eventually a big enough wind will come along and blow it away.... and it did.

After retrieving my now slightly lop-sided "Tent" from a neighbors yard, I decided to add some weight so I mixed up a slury of portland and water and sprayed it on. It made a nice hard shell,  and it never blew away again.

However after a few months of flexing in the wind was mostly just a bunch of cracked pieces.  Since it was the flexing that was the problem.  I got a bale of cellulose insulation, mixed up some paper-crete slury with it and used something like a  ceiling texture sprayer to put a thicker ( 1/4 - 3/8 inch ) layer on top of everything.  That was five or six years ago, except for the very center of the top where I didn't put much of a layer on it, it is still in fine shape and still makes a nice  garden shed. 

This was mainly just an experiment to see how cheaply I COULD build a structure.  Since I had a welder to tack the rods together I did.  I've lately been playing with recycling large boxes and pallets and I'm getting ready to do something similar with building an interior room inside of a warehouse.  The paper-crete has stood up incredibly well in my back-yard  so I'm going to try it for my interior room, but use the pallets and cardboard to build the basic structure.

Moral of the Story:

Yes, you can spray the paper-crete.  It makes a nice, mostly permanent coating.  Using cardboard for most of my structure, I'm going to do two or three layers and try to incorporate some triangular cross-section "Beams" to increase the mechanical structural strength. 

kenb wrote:
   Since it was the flexing that was the problem.   I got a bale of cellulose insulation, mixed up some paper-crete slury with it and used something like a  ceiling texture sprayer to put a thicker ( 1/4 - 3/8 inch ) layer on top of everything.   That was five or six years ago, except for the very center of the top where I didn't put much of a layer on it, it is still in fine shape and still makes a nice  garden shed.

kenb, would you please say more about the ceiling texture sprayer you used? Do you think one like this one available at Harbor Freight would work to spray a 1/4 to 3/8 inch mixture such as what you described?

Here's the link to the Wagner electronic texture sprayer that I'm wondering about that Harbor Freight currently sells for about $100: http://www.harborfreight.com/electric-texture-sprayer-kit-96123.html

Also, do you think that spraying your sort of papercrete slurry mixture onto a frame covered in sewn-together poly-net bags would produce a strong, durable weatherproof shell?

That's what I'm hoping to do with one experimental building this spring.

Another experiment is to build clay-papercrete wall forms and fashion a "hexayurt" of them, and then spray on a durable shell coating of clay-flour-fiber-crete. (The hexayurt, if you are not familiar, is an open source creation of Vinay Gupta that, in its simplest form, uses 4x8 foamboards. I'd rather fashion it of boric-acid-treated papercrete wall forms.)

Am trying to keep costs to the bare minimum -- out of necessity, and for documenting and proving that a durable structure can be built of recycled and reused materials for dirt cheap. Would really like to avoid having to buy a $265 stucco hopper and $500-plus compressor and $400-plus generator in order to be able to spray the shells and finish coats.

If one of these comparatively inexpensive electronic texture sprayers -- like the Wagner one -- would do the job -- albeit more slowly -- I would be quite happy. And that puts the upfront equipment investment much more within the realm of possibility in third-world environments.

I HAVE found plans for building a stucco hopper / sprayer for about $30 -- but it still requires an expensive (high force 8-plus cfm at 90 psi) compressor and a generator capable of producing 14-plus amps at 240 volts to run that sort of compressor.

The (free) plans for building the $30 hopper sprayer are found here: http://www.johnkingsley.ca/strawbale/sprayer/v1.html

If ANYONE has any experiences -- positive or otherwise -- of spraying papercrete or mud stucco slurry mixtures with a drywall texture sprayer, please share them.

Thanks,
ken

The artist and kid in me is most happy now. 



One question, what about internal humidity if one was going to build a greenhouse or greenhouse like addition?

Been making a hoop house with the walls done with slip pour of wood chips, bit of pulped paper and a bit of cement and lime.

Seems to be setting up fine. Plan to lime plaster and see how it holds up.

Here's a video a buddy put together of the build.

http://www.youtube.com/user/CommunityCultivators#p/a/u/0/BviWmwzwJp0