Alternatives To Wood

By Vicki Oldham

As we rush toward the end of the century, we are consuming the Earth's forests faster than nature's regeneration rates can match. The building industry is facing a scarcity of good quality lumber. The paper industry continues to pollute our rivers and streams with dioxin and chlorine, while sucking up trees at a ferocious rate. Global warming, drought, top-soil depletion, stream degradation, loss of habitat, and the extinction of species are some of the effects of non-sustainable forestry practices.

Most of us are aware of these sad facts. Some are on the front lines defending what is left of our forests. Unfortunately, we all, in some way, consume forest products. In order to "walk our talk" we need to make intelligent choices and use our consumer power to put our money where our mouths are. By:

* Using the wood products we have, more reverently and efficiently, where other materials will not suffice and where wood's beauty will be appreciated.

* Using waste resources (which are presently burned or buried in landfills) as alternatives to wood. Some of these resources are tires, bottles, and cans as used in earth-ship structures and agricultural waste used in bales and composite structural panel systems.

* Buying certified sustainably harvested wood to protect biodiversity. For "sustainably harvested" claims to be credible, they need independent, third party certification. There are less than thirty organizations world wide that provide forest management certification. Among them: (1) Silva Forest Foundation (BC); (2) Rogue Institute for Ecology and Economy (Ashland, OR); (3) Institute of Sustainable Forestry (Redway, CA) and (4) EcoForestry Institute (Portland, OR and in BC).

* Buying salvaged lumber. Although there is certainly not an inexhaustible supply of reclaimed building materials, it makes sense to reuse good wood as a natural resource that would otherwise be wasted while reducing the demand placed on virgin timber stands.

* Buying engineered and composite wood products. This new and growing industry uses wood fiber and shorter pieces of wood (formally destined to be scrapped or burned) to make structural lumber. However, there are a couple of potential drawbacks with this product. First, as mentioned in more detail below, toxics may be associated with the making of this product which would render both the process and the product less than desirable. Second, forestry based upon harvesting massive amounts of baby trees to supply the raw material for this product is exactly what we don't need and exactly what the timber industry would like us, as a society, to buy into at this point in time. Conscientious shoppers should make sure that their composite wood products are made from certified sustainably harvested and/or salvaged wood fiber and made with a non-toxic process.

* Buying recycled plastic lumber. Although plastic lumber is not yet structural it can be used for many outdoor applications such as fences, decking, benches, picnic tables and landscape borders replacing solid wood. Plastic lumber is rot and corrosion proof, and will not crack splinter or chip. One can purchase recycled 100% post consumer HDP and HDPE manufactured landscape products or lumber and keep plastics from our waste stream while providing another alternative to wood.

* Actively supporting the legalization of Hemp, so no trees at all will be needed for paper production. Cannabis Hemp is useless for smoking, it is an agricultural crop. Its pulp, fiber, oil and seeds can be used for paper, fabric, rope, canvas and food.

* Purchasing paper made from other non-wood fibers, such as kenaf or rice paper.

* Recycling, reusing and buying recycled paper products. Although, most people know that there are 100% post consumer recycled paper products, some are not yet willing to pay the few cents extra needed to purchase these products. As buying recycled paper products becomes more mainstream, prices will become more competitive as demand increases.

More than one-third of the lumber consumed in the U.S. is used for housing, and over 90% of new single-family houses are wood framed. Approximately 11,000 board feet of lumber are used to build a median-sized house. Wood is also the primary material used for subfloors, doors, cabinets, trim and siding. These applications have traditionally required lumber from stable, mature, large-diameter trees--old growth timber that presently comprises less than three percent of the existing timber base.

Framing accounts for up to 70% of the wood used in an average home. For floor spans and roof loads, good structural lumber has been hard to replace. Historically, lumber with the structural integrity needed for spans and loads came from the heartwood of old growth. Now that 90% of the old growth forests have been "harvested", timber is being cut from smaller diameter juvenile trees, that don't have the heartwood necessary to produce lumber with the structural integrity needed for framing.

The declining quality and quantity and increase cost of wood products has caused a movement toward a more efficient use of wood through the development of engineered wood products that no longer depend on the dwindling supplies of large dimensional timber, ie. Old Growth. Engineered wood products use low grade wood and or agriculture and paper waste to create all types of lumber replacements. I-joists, glue-laminated beams, oriented strand board (OSB), composition boards (plywood, particle and chipboards), finger-jointed lumber and trim are all engineered wood products. Again, consumers should demand that the wood fiber in these products come from environmentally sound practices.

I-joists have a very high strength-to-weight ratio and provide structural support for floors and roofs using one half the amount of wood that is required for traditional solid sawn joists.

OSB consists of small wood chips that can be harvested from fast growing trees, as opposed to the larger dimensional timber required for the manufacture of plywood. Hemp fiber can replace wood in the composition of OSB.

Finger-jointed lumber also provides an efficient use of the timber resource. Finger-jointing allows the mill to combine shorter pieces of wood into dimensional, structural lumber.

Unfortunately, most of the engineered wood manufactured today use plastic resins to bind, along with formaldehyde additives. But, there are a few responsible manufacturers who are using non-toxic glues, no formaldehyde, 100% recycled fibers and certified sustainably harvested wood. Again, the voice of the consumer must speak out and demand that these non-toxic, lower impact wood alternatives be made available.

Structural panel systems provide a material and labor saving alternative to traditional two-by-four and two-by-six stick framing and have been in use for over 30 years. With a core of expanded polystyrene (EPS) and OSB sheathing, these panels are structural, energy efficient and simple to erect, making them ideal for projects such as Habitat for Humanity. Not only are they quick to erect by un-skilled labor, but also the finished product is an energy efficient dwelling whose energy bills can be afforded by low-income inhabitants. A word about EPS, although the foam is derived from a limited petroleum resource, it only takes one quart of oil to create forty quarts of expanded foam which is in effect, mostly air. EPS foam core contains no CFC's, HCFC's, or formaldehyde.

There are a variety of entire house systems that use waste resources such as straw, tires, and waste agricultural fibers.

Straw bale houses are a low cost, low tech approach to home construction. The bales are stacked on a solid foundation, secured together and protected with thick coats of stucco. Bale houses are well-suited for areas with high seismic risk, severe climate, and where straw resources are available. The 2' thick walls can provide R-45 insulation. Straw Bale houses built in Nebraska at the turn of the century show very little sign of decay. Unlike wood, straw contains up to 60% silica which acts as a natural fire-retardant. The density of the compressed bales further prevents combustion.

ENVIROCOR(TM) panels are made from waste agricultural fibers. Manufactured from rye, wheat straw, or sugar-cane rind, these panels provide an economically sound method of avoiding the burning of these agricultural resources. The panels serve as roof and walls, eliminating the need for structural framing.

"Earthship" earth-sheltered, adobe finish houses use recycled tires, cans and bottles as substrate for exterior and interior walls. Rows of tires are set in place in a staggered fashion and packed with earth. These structures are best suited to southern regions where rainfall is low and adobe construction has been used for centuries.

Rammed Earth construction is another housing system that uses very little lumber. Although site dependent, (many soils are not compatible with rammed earth construction) because the cost of importing soil is both economically and environmentally expensive, rammed earth is a viable, resource and energy efficient option. Though rammed earth walls do not provide great insulation, their value is in thermal mass. Properly designed for passive heating and cooling, the "thermal lag"--the slowing of the heat transfer through the walls--allows the interior space to remain warm in winter and cool in summer.

One can't speak of alternatives to wood without considering hemp. In 1916, USDA Bulletin No. 404 reported that, "One acre of cannabis hemp in annual rotation over a 20-year period, would produce as much pulp for paper as 4.1 acres of trees being cut down over the same 20-year period." The paper is dioxin and chlorine free. Hemp can be used in bale construction and in the place of wood fiber for OSB and Envirocor panels.

After doing the research necessary to write this article, I have formed several convictions that I would like to share.

* Do to the high structural quality of manufactured engineered wood, no lumber larger that four-by six should be milled.

* There is very little justification for building stick houses (2x4 and 2x6 framing).

* Straw bale, panel systems, rammed earth, adobe and earth-ship houses are viable alternatives that can and should be used NOW.

* Hemp should be recognized for the valuable and versatile natural resource that it is. It should be legalized and its cultivation encouraged.


Copyright Mendocino Environmental Center 1998
Permission granted to excerpt or use this article if source is cited

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Last Update: 12/21/98