Tuesday, June 10, 2014

Wood Science 101 (15) - What Houses are Made Of

This video really impresses on the viewer is how much wood actually goes in a typical American home. Most folks think kitchen cabinets, wood floors, and decks when they are asked about wood in their homes...but as this video shows, there is much, much more wood that they don't see. Wall plates and studs, floor and ceiling joists, door and window headers, floor and wall panels, roof trusses, fascia boards, stair wells and treads...the list goes on and on. And none of this lumber is ever seen by most folks, except when they crawl into their attic.



Some fact checking reminded me that one 2400 square foot home may typically use 16,000 board feet of lumber, and 14,000 square feet of other wood products. And that's a good thing, as the USDA discovered and admitted in 2011.
USDA Leads the Way on Green Buildings, Use of Wood Products
 WASHINGTON, March 30, 2011 -- Agriculture Secretary Tom Vilsack announced today USDA's strategy to promote the use of wood as a green building material. At an event this evening to launch the International Year of the Forest, Secretary Vilsack will lay out a three-part plan addressing the Forest Service's and USDA's current green building practices.
"Wood has a vital role to play in meeting the growing demand for green building materials. Forest Service studies show that wood compares favorably to competing materials," said Vilsack. "In keeping with the Obama Administration's America's Great Outdoors conservation agenda, USDA has made a strong commitment to conserving and restoring our forests to protect watersheds, recreation, and rural jobs."
The strategy includes the following parts:
1. The U.S. Forest Service will preferentially select wood in new building construction while maintaining its commitment to certified green building standards. USDA will also make a commitment to using wood and other agricultural products as it fulfills President Obama's executive order on Federal Leadership in Environmental, Energy, and Economic Performance.
2. The Secretary has asked the U.S. Forest Service to examine ways to increase its already strong commitment to green building by reporting to him on ways to enhance the research and development being done around green building materials.
3. The U.S. Forest Service will actively look for opportunities to demonstrate the innovative use of wood as a green building material for all new structures of 10,000 square feet or more using recognized green building standards such as LEED, Green Globes or the National Green Building Standard.
In carrying out this initiative, Forest Service Chief Tom Tidwell issued a directive to all units this week calling for increased use of locally milled timber in all new agency buildings and facilities. Secretary Vilsack also directed the heads of all other USDA agencies to incorporate the Forest Service policy of using domestic sustainable wood products as the preferred green building material for all USDA facilities and buildings.
"Our country has the resources, the work force and the innovative spirit to reintroduce wood products into all aspects of the next generation of buildings," Tidwell said. "As we move forward with restoring America's forests, we are getting smarter and more efficient in how we use wood products as both an energy and green building source, which will help maintain rural jobs."
A recent Forest Service lifecycle analysis found that harvesting, transporting, manufacturing and using wood in lumber and panel products in building yields fewer air emissions – including greenhouse gases – than resource extraction, manufacturing and using other commonly-used building materials. In fact, wood –based wall systems can require significantly less total energy for manufacturing than thermally comparable houses using other common material systems.
Research arms of the U.S. Forest Service are also experimenting with new and innovative ways to use smaller diameter timber and leftover branches and limbs for wood products, which includes nanotechnology advancements and the use of laminate technologies.
- US Department of Agriculture, March 30, 2011 
Some folks still haven't gotten the message, though. For instance, the Resource Conservation Alliance, formerly known as WoodConsumption.Org, is on a mission to reduce wood usage under the assumption that wood consumption is a bad thing. In a section on their website entitled 'Is There Really A Shortage of Wood?', they say,
"The U.S. timber products industry spends millions of dollars each year promoting the idea that building with wood is an environmentally sound choice. Their ads claim that there are more trees in America today than ever before. The subtle trap is that these statistics do not differentiate between young sapwood trees and high-quality heartwood, or between diverse natural forests and single-species tree farms.
In the U.S. today, less than five percent of our original forest cover remains, and the clearcutting of old-growth forests continues. Intact forests support indigenous peoples, shelter wildlife, maintain the quality of fisheries and watersheds, conserve soil, moderate the global climate, and store much of the planet's genetic material. They may be our most important natural resource.
The construction industry uses 46 percent of the softwoods harvested in the U.S., for framing lumber and plywood, most of which comes from the Pacific Northwest and British Columbia. The U.S. Forest Service predicts that harvests from the Pacific Northwest have peaked and will fall steadily over the next ten years (Adams, 1994). Present demand has exceeded our forests' ability to supply lumber, even with the industry's prevailing unsustainable practices. British Columbia, however, now has one of the highest logging rates in the world: an acre of old-growth forest is clearcut every 66 seconds (Rainforest Action Network, 1995). It is imperative that we reverse this trend.
Changing the way we use wood in construction can alter the course of forest destruction, allowing us to save some forests from being turned into tree farms and preserving forest ecosystems for future generations."
The astute reader will note that the question put forward by the title of the section is never answered. Rather, there is sentence after sentence of somewhat related, and entirely misleading, statements that, if taken together, may lead some to think that...Yes, there really is a shortage of wood! When nothing could be further from the truth. North American forests are growing as wood consumption declines and rural development slows. And recent increases in lumber prices have much more to do with new regulatory costs, alternative uses and oil price increases than they do with timber supply.

Even more disturbing in the misinformation treadmill is the tendency by some local and state governments to take anti-wood stances in their definition of "green" development. Somehow, the folks in the Nebraska statehouse didn't get the memo from Mr. Vilsack. On the "Official Nebraska Government Website", we find these badly slanted talking points in a "factsheet" entitled "Minimizing the Use of Lumber Products in Residential Construction":
  • Although the U.S. is home to only 5 percent of the global population, it is responsible for over 15 percent of the world's consumption of wood.
  • A typical 1700 square foot wood framed home requires the equivalent of clear cutting one acre of forest.
  • Within U.S. national forests alone, at least 70,000 acres of old-growth timber have been harvested each year since the mid-1980s.
  • Tropical hardwood is especially vulnerable: 42 million acres of tropical hardwood were cleared in 1990, a 40 percent increase from 1980.
  • The traditional building method of stick-built framing has declined from approximately 86 percent in 1995 to 78 percent in 2000. By 2005, the forecast is for stick-built framing to decline further to around 71 percent.
- http://www.neo.ne.gov/home_const/factsheets/min_use_lumber.htm
 Let's take these point by point -

  • Although the U.S. is home to only 5 percent of the global population, it is responsible for over 15 percent of the world's consumption of wood.
Is that a bad thing? In other words, it's wrong that we consume more wood per capita than the folks in Iceland, or Greece, or South Africa? Could the reason be, perhaps, that we also produce 25% of the world's wood? 


  • A typical 1700 square foot wood framed home requires the equivalent of clear cutting one acre of forest.
Well, that sounds terrible, doesn't it? Of course, when one considers that the size of the forest in the United States has remained stable at around 750 million acres for the last 100 years, then a truer picture of the situation emerges. Let's say our economy booms again, and we get back up to two million housing starts per year. That's two million acres of forest, right? But two million acres is only 1/375th of U.S. forestland harvested in that year...in other words, it would take 375 years to harvest all the forest. But since typical forests in North America regenerate themselves every 50 to 100 years, that means...that's right, we'll never harvest it all. It's growing back much faster than we harvest it.
  • Within U.S. national forests alone, at least 70,000 acres of old-growth timber have been harvested each year since the mid-1980s.
What is old-growth timber? 100 years old, 200 years old, maybe 375 years old? Or perhaps old-growth timber is that lot across the road that has been there since you were a kid. Of course, old-growth timber will be harvested...and more is produced every day of every year of every decade. Today's 20-year old stand will be the old-growth timber of 2114.
  • Tropical hardwood is especially vulnerable: 42 million acres of tropical hardwood were cleared in 1990, a 40 percent increase from 1980.
Here's a hot-button issue. More tropical hardwood is being harvested. That's definitely a bad thing...unless you're a logging, sawmilling, or transportation family in Indonesia, Brazil, or the Congo. Then, the increase in international trade of your region's beautiful wood is bringing food to your table and prosperity to your country. Funny how that works.
  • The traditional building method of stick-built framing has declined from approximately 86 percent in 1995 to 78 percent in 2000. By 2005, the forecast is for stick-built framing to decline further to around 71 percent.
And the point is what, exactly? That home construction is getting more efficient? Why is that a case for using less wood in construction?

Come on, Nebraska. Get with it, and Go Wood. Remove or revise that silly fact sheet, and join the growing numbers of people in the world that understand wood is the best, most renewable and sustainable, building product Earth has to offer.





1 comment:

Anonymous said...

Great!!!