What is Papercrete?

Papercrete is a type of fibrous cement, or cement with fibers of some kind in it. These fibers can be just about anything, from paper (wood fibers) and cotton to hemp, jute, flax, wool and so on. These fibers add strength to the cement, just as glass fibers add strength to fiberglas. In the case of papercrete, these fibers can actually make up the bulk of the mix, resulting in a product that is both lightweight and strong. Watch a movie about Papercrete.

The ingredients in papercrete vary widely, depending on what it will be used for. For example, to make blocks for building a wall of a house, there really isn't any need to add anything to the basic formula of paper and cement. For load-bearing walls, some sand will add compressive strength to the mix. There is no need to add rocks or gravel, and doing so may damage the mixer blade.

If the papercrete mix will be used as mortar, as in building a wall from papercrete blocks, the addition of more cement will make the mortar stickier, and it will bond better with the blocks. If using the mix as a plaster to cover a papercrete wall, more cement will help here as well, so that the plaster sticks well to the wall and can be trowelled smooth. Adding cement makes the mix creamier and easier to use.

Qualities of Papercrete
Since Papercrete looks similar to concrete and is often used instead of it, let's compare them. Papercrete is far lighter in weight and has remarkable insulating qualities, unlike concrete, which is relatively heavy and often feels cold to the touch. Although Papercrete does not have the compressive strength of concrete, unless one is building something that requires the hardness of stone, like a five-story building, the hardness of Papercrete is often sufficient. You can hold a gas torch to Papercrete and it will not ignite or burn, so a house made from it is safer than one made from wood. It is easy to shape when cured and dry. It can be cut with an ordinary wood saw, carved and drilled. Try that with concrete.

Fibrous Adobe
A cousin of Papercrete, fibrous adobe is made from paper, clay soil and water. Or, it can be made with lime in place of soil. Fibrous adobe, sometimes called 'padobe', is much heavier than Papercrete, due to the amount of soil in it. It is essentially adobe with paper pulp. The paper fibers add much strength to the adobe, making it resistant to cracking and breaking under load.

Fibrous adobe is excellent for making blocks intended for walls and floors, due to its higher compressive strength than Papercrete. A Tow-mixer can also make fibrous adobe. The DVD shows Tow-mixers making both papercrete and fibrous adobe, as well as many building made from these materials. Most of the buildings have been standing over 20 years with little wear. A few of those building can be seen here.

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