Thursday, March 18, 2010

Living in Paper?

Douwe Wieberdink

Do you remember the story of the three little pigs and the wolf? The first pig built its house out of straw and the big bad wolf came along and blew it all away. The lesson learned was that we should build a strong and durable house to cope with all the dangers outside. And that was not the only thing I thought about when I heard that houses could be built of paper. I saw pieces of paper swirling in the wind or lying wet and sticky on the ground. I saw paper ripped apart and everything but a strong house. But, on the other hand, paper is principally wood, and wood is a good material to build with. Besides, there is plenty of paper and paper waste. In the United States there are about 1 billion (1,000,000,000) trees worth of paper thrown away per year, which is an equivalent of about 85,000,000 tons of paper or 680 pounds per person. (Recycling-Revolution) This does not even include the amount of water, oil, energy and space that is used to make this material.

Paper in itself is not strong enough to be used as a building material. Therefore it is mixed with Portland cement and sand to make a combination called Papercrete. Between 50 and 80 percent of its components are paper and about 80% of the blocks that come from this mix are air. The paper can come from a variety of sources: newspapers, magazines, books, junk mail, and so forth. The paper pulp and the cement are mixed with a little bit of water in a mixer and the result is a soggy substance that has to be dried like the clay based building material, adobe. The mixer that is used for this is a simple mixer that can be bought at any home improvement store.
When the Papercrete is dry it can be mortared, drilled, hammered and nailed. Just as adobe, it can serve as a filler between the poles or studs that form the frame, but it is about four times lighter than adobe. Paper is a fibrous material which means that when it’s dry there are little holes that contain air. This is what makes Papercrete such a pleasant building material; it is light, a very good insulator and it absorbs sound waves because of the open structure. So when this material is used in big noisy cities, little more has to be spent on insulation in order to keep the house quiet and warm/cold.

Papercrete is about a third of the weight of cinder blocks and it is flexible. Paintings, shelves or any other thing that we would like to hang on the wall is easily done because of the strength of papercrete and because it is so easy to drill. There won't be any problems using papercrete to build one or two story buildings, but papercrete does not have the strength of bricks or concrete; it is not made for big constructions.

Problems
Papercrete sounds like a perfect building material for residential living, which could lead you to believe there aren't any problems with it. But there are problems, and one is an obvious but very important one: it absorbs water like toilet paper. This can happen through condensation or through actual liquid. It would be relatively easy to avoid actual liquid on the surface of papercrete by not having any horizontal surfaces and by covering it. However, to avoid moisture, an entire protective coating will be necessary, which is a lot more difficult to create. Especially if you want to work with the material, such as drilling, the coating may be damaged and the papercrete loses its protection against water. When the protective coating is not done well, papercrete can wick moisture from the ground, which could lead to mold growth. The risk of this happening is constant, therefore papercrete has to be inspected frequently, especially in areas where rain or moisture are a constant factor.

Sustainable
Papercrete is mostly made out of recyclable materials which makes the production process cheap and will not put a lot of pressure on the environment. Portland cement, however does emit greenhouse gases and there are a lot of environmentally damaging waste materials used to make cement. These materials include: car and truck tires, hazardous waste, waste plastics, and pretty much anything that burns. But cement is used in almost any construction and it is hard to imagine it away from the construction site. However, using other components, such as clay, would be an option in some cases.

Papercrete is a new material. As it seems now, papercrete has a high life expectancy but there has little research been done and it has a limited track record. Time will teach us if this material will prove to be viable and safe. This research is very important for the success of papercrete because at this point, engineers and architects are hesitant to use it. They just don't know the (long-term) effects, and building something with a relatively unknown material is a high risk. Research is vital, especially if we want to make papercrete a success story for a high amount of constructions.

So far there are very few commercial companies active in making papercrete. The only one could find is in Mason, Texas. (Please let me know if you know others). Mason Greenstar is a U.S. Green Building Council Member (USGBC, http://www.usgbc.org) which indicates that it wants to build in an environmentally friendly manner, and that the Council recognized that. Having this membership is important for the success of papercrete because it proves that this material is environmentally friendly and it gives hope that the life expectancy is high, as well.

Costs
Because papercrete can mainly be made of recycled paper the costs are reduced significantly. On the Architecture Week website, Goldon Solberg says that the cost of materials for a house can be as low as $5 per square foot. This is $54 per square meter. In comparison, if we used bricks the cost could double. But papercrete is mainly made of material that is considered peoples’ waste. This means that if people want to make constructions of papercrete in small amounts, they can actually find most of the “ingredients” around their houses, which brings the cost even lower.

If papercrete could be made in large quantities at factories, the components would have to be found somewhere else in greater quanities, but the cost would still be low. Besides, the weight is a lot lower than other building materials such as bricks and adobe, which keeps the transport cost low.

For OS-House
This brings us to the final question. Will papercrete be a good material for the OS-House design competition? As far as we can say now, papercrete is a 'green' building material. It uses mostly waste or recyclable products that can be found locally all over the world. The material can be made easily with just a mixer in anyone’s backyard. Even if you can't do that, the transportation costs would be low because it is such a light material. A problem is that one of papercrete’s main components, cement, is an environmentally hazardous material, but this can relatively easily be substituted by other components. Another problem can be the moisture in the building blocks. To find a good product that can coat papercrete can become a problem in some parts of the world, but this would have to be researched further. A major advantage is that papercrete can be very inexpensive. As long as the builder uses 'waste' materials, the cost can be kept very low. Cement would be the most expensive component, but when this is substituted by something more environmentally friendly, the cost could actually be lower.
OS-House wants designs for the lower-middle class income families from developing countries. These families usually do not start to build a five-story house immediately but, as the family increases, the size of the (modular) house may increase as well. It will be a challenge to adapt to that.
Alltogether I think that papercrete is a wonderful material and when it proves to be long-lasting, it may have a great future in the developing as well as the developed world.

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