What is Papercrete?
Papercrete is essentially a type of industrial strength paper maché made with paper and cardboard, sand and Portland cement. There are many varieties of Papercrete possible. Essentially, the constituents when mixed in different proportions result in PaperCrete of varying properties.
The basic constituents of Papercrete are:
- Paper: usually waste paper such as used newsprint or cardboard.
- Aggregate – coarse aggregate or fine aggregate such as sand may be used depending in the desired strength of the Paper Crete.
- Cement: it is used as a binder and used to provide strength and rigidity to the Paper Crete.
Pouring the Slurry into a Panel Mould
A tried combination is 60% paper, 20% sand and 20% cement. The method of making Papercrete is very simple. The dry ingredients are mixed with water in a mixer to form slurry. The slurry is cast into blocks or panels and allowed to dry in the sun.
When it hardens up, papercrete is lightweight (its 80 percent air), an excellent insulator (R 2.8 per inch), holds its shape even when wet, and is remarkably strong (compressive strength of 260 psi). And, since it contains paper fibers, it has considerable tensile strength as well as compressive strength (Solberg, 2000).
Papercrete is suitable for making low cost homes with limited longevity and durability. It is also suitable for making community rooms, sale booths, storage rooms and dwellings for livestock. Papercrete can also be used as a plaster. It can be sprayed on walls to give them good sound and heat insulating properties.
Benefits of Papercrete
- Raw materials are very inexpensive and freely available.
- Equipment used is relatively low-tech and inexpensive.
- Has high compressive strength.
- It has excellent heat and sound insulating properties.
- PaperCrete is light weight and can be used to make inexpensive roofing alternatives.
- PaperCrete is very workable and can be formed into different shapes such as blocks, panels and sheets with ease.
- It does not catch fire easily but smolders for hours.
Limitations of Papercrete
- Poor moisture resistance
- Susceptible to termite and mould
- Disintegrates when exposed to water for prolonged periods of time.
- Low longevity
- Expands and contracts frequently leading to cracks and buckling
- Poor tensile strength.
PaperCrete is a recent technology and its use is limited to experimental and recreation use. This has also resulted in the limited knowledge base about the technology. PaperCrete when used in conjunction with more traditional building techniques has yielded positive and encouraging results.
Papercrete Wall Panel
The code compliance of PaperCrete remains sketchy simply because there are no codes for PaperCrete. Many rural counties, particularly in the West, there are either no building codes or the existing codes are loosely enforced. In New Mexico one can apply for an experimental permit. This requires drawing up a set of plans and having an engineer sign off on them.
Using PaperCrete as a wall filler is more likely to gain acceptance with building inspectors. One PaperCrete house has been built with a permit in Arizona. The building inspector insisted that it be built post-and-beam, with the PaperCrete used only as infilling (Solberg, 2000).
A Papercrete and Glass Bottle House