What Is Papercrete?
Papercrete is made from recycled paper with a small amount of cement and sand added. The ratio is 60/20/20. The paper/concrete/sand mixture is
stirred in a large barrel, much like a blender, until all paper is shredded and evenly mixed with the concrete and sand. Papercrete can be mortared,
drilled, hammered, nailed, used as plaster and as an infill between poles or studs. Recently, some people made the mixture without cement, and
created Fidobe or Paper Adobe. These products are dense building logs used in construction.
While researching, I found a gentleman that had made a mixer out of an old 55 gallon drum, which was mounted on an old car axle. A unique gearing
system attached to an old lawn mower blade did the mixing. He would hook this contraption behind his car, take a slow drive around the block, and
have perfect papercrete.
How Is It Applied?
Papercrete is handled much like adobe. It can be made in smaller bricks or can be used much as cement is, and poured into a monolithic wall. If
papercrete is poured in a monolithic wall, the density on the bottom will be much greater than on the top. The papercrete will be cut off from the
air, causing drying issues. This can cause pockets, creases and voids in the wall. Papercrete will also shrink 30% in height when drying. It stands
to reason that building using the slip form method is the safest bet.
One method of construction is the wattle and daub technique. In this construction, a wall is woven using poles and reeds, and then the papercrete is
applied. This method has been in buildings dating back to primitive times.
Another technique used is the slipform method. In this method, the papercrete is poured into the forms creating the exterior walls. Forms are placed
one on top of the other until the correct height is reached. The papercrete slurry is used to fill joints and reinforce the blocks. This type of
construction is very strong, and is used in high rise buildings, silos, and multi-story buildings. Using this technique for building a papercrete
house is a good choice.
Papercrete has the disadvantage of not being waterproof, and extra care must be taken during construction to insure that the site is completely
waterproof on the exterior. The exterior can be finished with one layer (1/2") of homemade stucco, the mix being Portland cement, slick lime, masonry
sand, and water. Be sure to apply evenly, and take great care to ensure that the exterior is completely waterproof. The walls can then be painted
with latex paint, using several coats.
The interior can be treated in the same manner. Environmentalists try to build these constructions using the least amount of wood possible. Interior
papercrete walls are often painted just as the exterior walls are - with latex paint. A white lime wash, which is very nice looking, can be applied to
Flooring can be made from adobe, or a mixture of adobe and papercrete. Often, papercrete is used as a subflooring, thus making a good thermal
barrier. Flagstones are also often used for flooring. Papercrete, unless mixed with greater proportions of cement, must be covered with another
material because papercrete flooring by itself will be indented by heavy tables and chairs.