Judith, is the building on your blog, the same one that was started at
the Abiquiu Papercrete Gathering?
--- In email@example.com
, JUDITH WILLIAMS
> I have had problems with shrinkage of papercrete away from wood. I did
an 11' slip form wall between 2 large posts, 12" wide. 2 years later I
can see that it has really shrunk a lot. This wall has shrunk in about
4" from the vertical logs that serve as posts. Also about 2" on either
side. I suppose that if I were to finish this wall (the property has
been sold and its future is uncertain) I could fill in the gaps with
more pc or some foam insulation.
> This is why with the newest projects I have used forms that allow the
papercrete to flow around the entire perimeter of the building
uninterrupted. I have left a 4' opening for a door (to be widened later
after all shrinkage is done) but was sure to make the courses under and
over the door as strong as could be. So far I've seen only small
inconsequential cracks around the top corners of doors in the first
building I did this way. I have made some improvements to the second
building and see no cracks.
> I use a mix of soaked cardboard, about 3) 55 gallon drums per 200
gallon load to which I add 1/2 bag of cement. I also have access to
pumice and add about 15 large shovels full. I believe this does a lot to
increase mineral content and minimize shrinkage. I have used sand in the
past but not any more. It seemed to sink to the bottom of the mixer no
matter what I did. Now if I don't have any pumice I just use the
cardboard and cement. The more cement the less shrinkage. If you are
slip forming then weight of the cured product isn't as important. When I
first started making blocks I used a recipe that called for 2 bags of
cement. Now I am using those blocks in my slip formed walls and can't
believe how heavy they are.
> I am now about 2/3 done with my roof on the first building. I put up
vigas about 30" apart and tacked a double layer of chicken wire over
them and down the sides a little bit. I pour the slurry on top and
surprisingly enough it doesn't fall through. I am careful to continue
the roof papercrete so it flows right into the walls. I want this to me
as monolithic as possible. What this building reminds me of is an upside
down styrofoam cooler. I have embedded some old blocks in the roof to
use them up and take up some space (less slurry to mix and lift to the
roof). So far it's coming out very well.
> Your mixer sounds like a good one. Spaceman and I have been discussing
using a small stationary mixer and somehow putting it right on top of
the wall forms. That way you could mix up the slurry, empty it right
into the form then move the mixer along as you go. If I had some
mechanical ability and knowledge of tools etc I would try this. If
anyone is interested in coming to work with me and wants to try this
they are more than welcome.
> Anyway, good luck with your shed project. It sounds like it's going to
come out very cute.
> Follow progress on the new project at http://www.papercretebyjudith.com/blog
> More papercrete info at http://squidoo.com/papercretebyjudith
> To: firstname.lastname@example.org
> From: carlsondanjames@...
> Date: Thu, 5 Aug 2010 10:14:55 +0000
> Subject: [papercreters] Shrinkage?
> First off I would like to say 'You guys/gals are awesome!!'. I love
like minded people. Everyone I talk to about papercrete looks at me like
I have two heads.
> My first papercrete project will be a shed in the backyard. Something
that looks like a small cottage with a 3' front porch, front door with
windows on either side.
> I was thinking 12' X 10' with 8' walls, 8' double doors in the side.
Foundation of cement block 12" below and 12 above grade. Framing would
consist of rough cut lumber, 4x4 posts for the corners plus frame work
for the doors and windows, topped with 2x4.
> I am now thinking that shrinkage is going to be a problem and the
framework will have to go and make the walls 10" wide and load bearing.
> The roof is also bugging me because I want it made of papercrete as
well but I need some suggestions on how to make that work.
> My paper material will be box cardboard, recipe will be barrel filled
with pre-soaked cardboard, 1/2 bag of cement, filler ? (don' know yet)
> My mixer is going to be a 45 gallon plastic barrel with a 3" waste
outlet that they use in campers, the mixer is going to be a 1/4 hp
electric motor with a pulley connected via a belt to a 3 1/2' metal
shaft with mixing blades on it.
> In a 10" thick wall what is the width shrinkage? Does it shrink in the