There are a growing number of people who are in business offering workshops about papercrete to would-be owner-builders, and this is good, but what we are talking about here is mainstreaming papercrete as a residential and commercial building material.

Mike McCain's operation produces jumbo blocks in bulk.

Presently, papercrete in all its forms is a victim of Catch-22. It's a question of market. Without a market, there's no investment. Without investment, it’s difficult to develop a market. Right now, it's a challenge to convince entrepreneurs to invest in block making operations when few people even know what papercrete is. That will change, but change takes time, and investors want a quick return on their investment. So, individuals interested in starting a papercrete business are probably going to have to do it on their own for the time being.

The fact is that there are markets for papercrete - just not a mass market yet. So, to get started, an individual is going to have to develop his or her own market - go out and get an order for some blocks and then fill the order. The largest potential market for blocks at this moment is as "in-fill" for homes.

Sheds under 120 square feet (12 square meters) usually do not require a permit.

Since papercrete is not formally approved as a load bearing building material, it cannot legally be used in most localities to support a roof. But as “in-fill," the papercrete walls are built between roof-supporting posts and filled in between them, hence "in-fill." The posts are connected to the foundation at the bottom and tied in to beams on top. The roofing system is built on top of the beams. This approach is commonly called “post and beam." Papercrete is a great solution for this application. Of course, with some limitations, it can also be used to build garages, sheds and other structures, which do not house people. Another market is garden and perimeter walls, or other landscaping purposes like ponds.

A papercrete pond, which has been holding water for three years, with no leaks.

Papercrete can be made to hold water so it can be used for swimming pools, Jacuzzis, spas etc. ; all markets in and of themselves. But let's get back to making blocks and building homes. What are the challenges? The first challenge is getting good information.

INFORMATION

It makes obvious sense to verse oneself on the properties and characteristics of papercrete, whether sold as blocks or employed in building homes. The only way to do that is to read everything available on the Internet and contact others or read material from others who have already worked with the material. The frustrating thing about doing that is that previous builders have varying and sometimes conflicting recommendations about how to do things based on their experience. Most of the knowledgeable people working with papercrete have not had the time or opportunity to compare notes with other practitioners about what works and what doesn't. What each person feels is true is only true based on that person's experience. There are differences of opinion on just about everything - from the "best" mix to the "best" building method. For example, the construction approach described on this website specifies rebar in the construction of the walls. At least one practitioner feels that rebar isn't necessary at all because, when cured, papercrete is monolithic. The rebar approach was adopted on this website because the structure built using it was successfully permitted. What is needed is a standard building procedure, which can be permitted anywhere in the country. Part of the problem with a standard building procedure is papercrete's flexibility. It can be poured, slip formed, formed as blocks, or as tilt-up panels, "harled," daubed, made into roof panels, etc. A comprehensive building procedure describing all of these methods will eventually emerge but it hasn't yet. So the best approach is to decide what product is to be marketed and then set about defining the building approach which fits the product. No one ever said it was going to be easy.

VOLUME MIXERS

Most of the equipment needed to work with papercrete is standard off-the-shelf hand tools. The one exception is the mixer. One of the barriers to producing papercrete in bulk is the need for a low cost, high volume mixer. Conventional concrete mixers do not work well to pulp papercrete, but if the paper is already hammermilled, a conventional mixer will work fine. So far, only a few people are working on equipment to produce papercrete in volume. This is true because most of the people using papercrete are individuals busy building their own homes. Part of the reason that volume papercrete mixers haven't been developed yet goes back to the market for papercrete. Why invest in a developing a mixer for material which isn't in widespread demand. The other reason is that the people using papercrete are using it  because it is cheap. Environmental and other benefits aside, they are using it because they don't have a lot of money. So this group doesn’t have the time or money to start engineering volume mixers, establishing a national market and seeking nationwide approval. This would be an excellent, high return area for the federal government to spend some dollars for research and development.

There are, however, a few individuals who are persevering and working on several different approaches to volume mixers. Each approach depends on a different way to make the mix and therein lies the difficulty. As mix formulas become more complicated to accommodate low-cost mixer design, the mix itself becomes more expensive, which lowers the profit margin to a point where it doesn't make sense to make the blocks that the mixer is designed to produce. A number of innovators are working on this issue, which embodies another Catch 22. Which should come first - the approved mix or the approved mixer? Developing a mixer for use with a given mix, which doesn't meet codes or is impractical from a cost standpoint, is a waste of time and money. It is also a waste to develop and test a mix  which cannot easily be prepared in volume. Regardless of this challenge, there are people working on volume mixers now.

Another challenge involves perceptions.

PERCEPTIONS

Papercrete homes can be built beautifully, with all the amenities, for much less than conventional housing.

Most people accept their perceptions as fact. "You only get one chance to make a first impression," as the old saying goes. This is as true of papercrete as anything else. If a person sees a home made of papercrete and the home is minimalist in appearance, that person will equate papercrete with minimalism. If a person sees a video about papercrete, and the presentation is amateurishly done, that person will conclude that papercrete is not to be taken seriously. Once the impression is made, it's difficult to change. But luckily, some artist-builders are starting to work with papercrete and are radically changing the early impressions of it. There will be a day in the not too distant future when papercrete will be the material of choice for beauty, value, and durability.

APPEARANCES

A home built using innovative or "alternative" construction methods doesn't have to be uncomfortable to live in. In fact, many of these homes are more interesting to look at and more healthful and economical to live in than conventional housing - and they usually cost a lot less to build. Shrinking resources and expanding environmental concerns necessitate closer examination of alternative building techniques, which at first glance may seem untenable but turn out to offer dividends measured in many dimensions.

Papercrete, when made with Portland cement, looks a lot like concrete. This is a blessing and a curse. Many properties of papercrete make it more flexible than concrete, but in some ways it doesn’t act or perform the same as concrete. This leads some people to think that it isn't as "good" as concrete. The fact is that both materials have their strengths and weaknesses and both need to be used properly to be most effective.

Papercrete blocks are not always perfectly smooth or square, but it doesn’t matter.

When I first saw a pile of papercrete blocks, I was struck by how rough and irregular they were and how much one block differed from another. This turns out to be completely natural. Inconsistencies in mix (see Mixes), the type of paper used, the makeup of the paper, ambient temperature, humidity, hours of sunlight  and other factors can cause changes in the final product. Papercrete is very forgiving but not completely consistent and, fortunately, it doesn't have to be.

As papercrete blocks dry, they often slump or sag lengthwise and taper inward, from top to bottom, around their perimeter. This happens especially in a wet mix because there is less weight at the top of the mix when it is poured and more weight pushing out at the bottom. The result is a block that is not completely rectangular when viewed from the end, and may be bent slightly over its length. In addition, the surface of papercrete is often rough and the entire block may have quite a few small voids in it. At first, papercrete blocks seemed a little primitive to me compared to the perfect dimensions of concrete blocks and bricks. I quickly came to understand that I had to let "papercrete be papercrete." It's not concrete or brick or adobe. It's something different and the irregularities are actually not flaws but characteristics. In reality, the irregular shape is of no consequence and the rough surface and voids actually allow one block to adhere better to the next block when mortared together with a wet layer of papercrete.

Lex Terry applies papercrete stucco. No stucco wire is needed.

When a wall of papercrete blocks is completed, it will never be perfectly smooth - no matter how much care is taken in laying the block. It doesn't matter that it's not smooth. In fact, being rough helps the exterior stucco and interior finish to adhere to the wall. Areas that protrude too much can easily be trimmed with the claw side of a hammer. Areas that are too concave are simply built up with papercrete stucco. In the end, being careful with the outside stucco and the interior finish covers all seeming imperfections.

Walls made in tall forms, like those used in monolithic concrete pours, have their own unique characteristics. As explained under Forms, trying to pour layers of great thickness results in a great deal of compression at the bottom of the form. This can cause the wall to dry very slowly and unevenly, and to shrink a great deal, resulting in pocketing that appears as voids and crevices. Usually these voids can easily be patched with a richer mix of papercrete and Portland cement or some other binder, which dries in the cracks and voids without shrinking. Once again, when the wall is covered outside and inside with stucco, or some other finish, the seeming imperfections are no longer visible. The final surfaces can be made as perfect as time and patience permit. So marketing should always be based on the final product, not on the process to get there.

HYDROPHILIC

Hydrophilic means having an affinity for water; readily absorbing water. Papercrete is hydrophilic. When I first learned that, I thought it was a fatal flaw and set about finding a way to make papercrete waterproof - in other words to make it "hydrophobic." There are ways to waterproof papercrete without affecting the positive properties of the material. But even without waterproofing, when papercrete absorbs water (if it was originally mixed with sufficient binder) it doesn't lose its shape. In other words, it doesn't turn into mush like un-stabilized adobe.  When water goes into untreated papercrete, it quickly evaporates as soon as the rain (or other source of water) stops. Untreated papercrete is temporarily heavier while carrying the water, but as long as it can shed the water through evaporation (in other words as long as it can breathe) the water is not harmful. If the water is trapped and retained, mold, mildew, fungus, etc. may take hold. Trapping water in any building material is to be avoided. That's why it's best to either let the material breathe or moisture proof it completely. Many structures with untreated papercrete walls and roofs have been standing for years with no apparent ill effects, but waterproofing papercrete is practical and possible.

It might not be a great idea to build in a flood plain with papercrete but plywood, drywall and other materials don’t do well in water either. Building in flood plains will probably be prohibited in the not-too-distant future, because insurance companies are trying to refuse issuing insurance to homes constructed in flood prone areas.

It would seem to make sense that papercrete would do best in dry climates of the world like the Great American Desert, which comprises a good deal of the western United States. However, there are homes made partly of paper in locations like Vancouver Island - off British Columbia, Wisconsin and even Rockport, Massachusetts. The Paper House in Rockport was built in 1924. It's in-filled with newspapers glued together and covered with varnish. Kelly Hart's home, in the mountains of Colorado, has been through over 200 freeze-thaw cycles since it was built and has exhibited no degradation or change in appearance. So humidity, water ,and snow may not be as great an issue as previously thought.

FLAME RETARDANT

The term "flame retardant" has to be differentiated from "fireproof." Unless you add a significant percentage of non-flammable material to any papercrete mix, it will burn. It may not burn with an open flame, but it will smoulder like charcoal and eventually be consumed. Papercrete made with a 4-to-1 ratio of cement to paper, by weight, won't burn at all, but that  amount of cement is too costly and may negatively affect R-value. Papercrete made with a 1-to-1 ratio of cement to paper, by weight, will smolder like charcoal, but does not burn with an open flame. Smoldering with no flame is considered flame retardant.  Being only flame retardant could result in an unlikely but dangerous scenario. One practitioner is particularly sensitive to the possibility of a roof collapse should wide areas of a papercrete wall smolder for hours without detection.

But another practitioner tested this possibility and thinks that such an occurrence is highly unlikely. He bored a three-inch hole in a papercrete wall and emptied an entire can of charcoal lighter fluid inside. He managed to get the papercrete to begin to smolder, but it would not continue to smolder for long because of lack of oxygen. It was suggested that fireproof mortar (high percentage of Portland cement or other fireproof binder) be used between the blocks as walls are erected, and fireproof stucco be used on the outside of the home to "encase" the blocks in fireproof  "containers." This would limit a smoldering fire to the destruction of only one block in the unlikely event that it should ever occur at all. 

In late 2005, we did some additional informal testing on papercrete and fire.  A simple mix of boric acid and borax will completely firepoof papecrete.  See the "Informal Tests" section in Tests.  In early 2006, we have been doing experiments with sand content. Adding more sand increases compressive strength  and fire retardancy, but we don't know how much it effects "R" value yet. We're running tests in the February, 2006 time frame.

So there are significant challenges going into business making papercrete, but every beginning is difficult. One thing is certain. Papercrete is a concept whose time has come. Papercrete, in its present form, or something similar to it will have to be developed to stop the avalanche of our forests into our landfills. In any challenge there is also opportunity. The best future is for those who find the opportunities in the challenges and benefit themselves, others and the environment with their solutions.