Innovative people across the USA are experimenting with ways of using paper and other recyclable materials to build houses. One of the most promising is papercrete.
What is Papercrete?
Papercrete is made from paper pulp, water, and a small amount of cement. Traditional concrete is made with a bunch of sand or gravel held together with cement. Because the sand can’t hold together on its own, it requires a lot of cement to hold it together. Paper, on the other hand, is fibrous and holds together on its own. Therefore, it requires much less cement.
How Do They Make Papercrete?
The first step in making papercrete is pulping the paper. Any paper can be used, including old newspapers, phone books, and cardboard. The paper is ground up with saw blades in a large barrel, and mixed with plenty of water to make a slurry.
Once the paper has been “pulped”, the builder adds cement. Depending on what the papercrete will be used for, more or less cement is added – more for harder surfaces such as floors; less for walls.
At that point, the papercrete is a thick, gray paste and can be used exactly like concrete.
Many times, the builder will choose to make bricks. The papercrete is simply poured into molds, then set out in the sun to dry. Once dry, the bricks can be used like traditional bricks – using more papercrete as the mortar to hold the bricks together.
Because the paper is absorbent, there must be some type of coating on structures made with papercrete. Any water resistant paint or coating may be used, but Stan’s favorite is a lime wash made with lime, water, salt, and nepal cactus. This lime wash stays cool even in direct sunlight, which adds to the insulating ability of the papercrete itself.
Advantages of Papercrete
There are many advantages of using papercrete in construction.
- Environmentally friendly: One of the major components in landfills today is paper. By using paper in building, we can significantly reduce the amount of paper ending up in landfills.
- Lightweight, but strong: It is much easier for someone to lift 5-pound papercrete blocks all day than 35-pound concrete blocks.
- Easy to use: Papercrete can easily be molded into just about any shape. Decorations can be made as though using papier mache.
- Insulating: When using concrete, heat from the sun will heat the wall up and the concrete will allow that heat to pass all the way through and radiate into the interior of the house. Paper, on the other hand, does not allow for the transfer of heat. Even though the sun may beat down on the papercrete wall all day, the heat will not transfer through to the interior.
- Low cost: Because structures made with papercrete are 95% recycled materials, the cost is very low.
Disadvantages of Papercrete
Most of the disadvantages of building with papercrete have to due with the relative rarity of the materials.
- Machinery designed for use with traditional concrete are built for use with very heavy materials, therefore the machines are heavy and expensive. While those machines certainly work for papercrete, the extreme durability is not necessary. Since papercrete weighs a small fraction of traditional concrete, lighter-weight machinery would easily suffice. However, because of the small number of people building with papercrete at this time, that type of machinery is not commercially available, which means that one must either buy the expensive machines or build their own.
- As papercrete grows in popularity, it will become harder to find enough paper. Right now, there is an overabundance of excess paper, and one can get as much paper as you want for free. As papercrete grows in popularity, people will realize there is a market for old paper and start selling it – thus the cost of building with papercrete will go up.
- Another disadvantage to papercrete is that it absorbs water. One must be careful to put a good protective coating on all exterior surfaces that may be exposed to rain. It is also difficult to use on the ground because it will absorb water from the surrounding earth.
- Papercrete is not particularly ‘structural’, which means it can’t be used over doors and windows without some additional support – either wood or traditional concrete.
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