• Thermally Modified Lumber asked

    ON August 1st, 2011 AT 8:17 AM

    I have been looking into Thermally Modified Lumber and its environmentally benefits. There seems to be numerous advantages to this product. Have you done any research into this product and if so what have you found?


    ON August 1st, 2011 AT 7:17 PM

    Thermal treatment of wood (treating of wood at unusually high temperatures during drying) creates a mild pyrolysis that modifies lignins and hemicelluloses resulting that wood becomes less hygroscopic (takes on and gives off less water) which, as a result reduces shrinkage and swelling in particular and, in combination with some new chemical bonds formed within
    the wood, make it more resistant to fungal degradation.  Also, the reduced hygroscopic nature of the wood makes it less attractive to other degradation sources such as carpenter ants and the like.


    Environmentally, the great benefit is the lack of a need for added chemicals with a resultant product that is highly resistant to shrinking, swelling, and decay.  At the same time, there is a fairly large increase in the amount of energy required to produce the product -although I have seen no specific research making actual comparisons by product.  The other nice thing is that it is fully biodegradable over the long term and is thus disposable in an easy manner.


    There is some anecdotal evidence, although certainly not complete nor conclusive, that thermally treated wood does not finish well with all stains and paints - so some care is needed there.

    Add new comment
  • Sally asked

    ON June 26th, 2011 AT 1:51 PM

    A friend recently traveled from Pennsylvania to the mid-west and noticed something was causing pine trees to "die from the inside" as she described it. Is there a disease attaching pine trees?


    ON June 27th, 2011 AT 1:51 PM

    There are a couple of different possibilities to explain what your friend was seeing.


    Pine trees that are stressed (heat, drought, etc.) often shed "old" needles first. These older needles happen to be "inside" the tree, closer to the main trunk. This also happens naturally as pine trees grow, but the loss of the internal needles can sometimes appear as a significant loss of needles.  Generally, loosing these older needles is not as much of a health concern as when the "new" needles near the tips of branch wilt and die.

    It may also have been trees affected by the disease known as scleroderris canker. This affects all hard pines, and principally red pine.  There are, of course, a number of other pine tree diseases, including needleblight, needle cast, rust, pine wilt, pine wood nematode, shoot borer, littleleaf disease, and others.  Information about each of these is readily available via the internet.


    Finally, if these were trees along the roadways, they may have been impacted by road salts or other chemicals.



    Add new comment
  • Janus asked

    ON June 18th, 2011 AT 9:23 AM

    Is it true that trees under 100 years old are not mature and produce pethy
    wood with a shorter life expectancy for products made from them?


    ON June 22nd, 2011 AT 9:23 AM



    With regard to the statement posed, this is not true.


    It is true that trees, when young, produce a type of wood that is different than the mature wood formed later in life.  This wood, that is commonly known as juvenile wood, has lower strength and a number of other properties that are different from mature wood and generally less desirable.  The period during which a developing stem produces predominantly juvenile wood is the first 5 to 15 years of life.


    Related to your question, it is worth noting that different species of trees reach maturity at different ages, with maturity also influenced by site and climate.  Some species, such as birch and aspen, become mature at about age 55 to 60, and begin marked natural mortality by age 70 or so.  Others may not reach maturity until age 85 to 120 and beyond.


    In all forests, competition between trees combined with natural aging processes translates to changing dynamics over time.  Growth rates in young trees and newly established forest stands  tend  to  be  rapid.   As  trees  grow in size  and  crown closure occurs, competition between  trees intensifies,  leading to the death of some  and enhanced prospects for others.  Later, the rate of growth slows and vigor begins to decline for even the dominant trees in a stand as a result of aging, with the rate of accumulation of new growth often reversing (i.e. more wood is lost to decay than is added through new growth) at advanced ages due to increasing natural mortality.


    Wood quality in these very old trees is not necessarily better than that in younger trees, but one advantage to larger diameter (which can come with older age, or as a result of growth acceleration after the juvenile period has passed), is that the proportion of juvenile wood in the larger diameter stem is lower.  Thus, when lumber and other structural products are produced from larger trees problems attributable to juvenile wood can be avoided or minimized.


    I hope that his helps.  Let me know if you have any additional questions.

    Add new comment
  • Jeff asked

    ON May 31st, 2011 AT 11:15 AM

    I live in Florida. I have two beautiful palms in my house. One is starting to brown at the fronds. The others' fronds are starting to grow limp. Am I watering too much or too little? Or do I need to some fertilizer on them? HELP!


    ON June 1st, 2011 AT 11:15 AM

    It is difficult to diagnose a tree problem from a distance, but you can check to see if water might be a problem just by feeling the soil (if it is soggy, you should water less – if the ground is dry and cracking, you could water more). For the best advice, you should consider contacting a local qualified arborist or Extension agent. You can search for a certified arborist at this site: http://www.isa-arbor.com/faca/findArborist.aspx You can look for a local Extension agent through this site: http://solutionsforyourlife.ufl.edu/map/


    You may also want to visit the following sites for more information:



    Add new comment
  • Edith in Illinois asked

    ON November 11th, 2009 AT 5:33 PM

    Have you done, or do you know about a comparison for making the choice between live and artificial Christmas trees?


    ON November 16th, 2009 AT 3:33 PM

    Thanks for your question! The short answer is that if the choice is being made based upon environmental considerations, there is research evidence to support live trees as having less environmental impact.


    In a life cycle assessment of live vs. artificial trees it was determined that an artificial tree would need to be used for at least 20 years before the environmental impacts would be less than purchasing a live tree each year.  On average, most artificial trees are kept about 6 years. The full study is available at:



    In terms of environmental benefits, live trees are often locally available from growers and sellers within the region, trees sequester carbon, are replanted, renewable, biodegradable and non-toxic.


    Naturally, there are other reasons why people choose artificial trees, including convenience, and if someone is able to keep using the same artificial tree for more than 20 years the environmental impacts may be more in balance.



    Add new comment
  • Kari asked

    ON October 2nd, 2009 AT 1:17 PM


    "I cannot conceive of a situation where more toxic treatments such as CCA, ACQ etc. would be considered green, or even allowable in green building." - Doc


    I read your above comment from the Dovetail website in a question & answer segment -“ this particular comment came from an inquiry on BluWood


    I have attended a few of your seminars and wondering what your latest thinking is on chemically preserved wood?


    I am also researching the 'green' value of composite / vinyl / plastic decking. I did not find any LCA research on the BEES website. Any help?




    ON October 5th, 2009 AT 1:17 PM

    I have to admit I am skeptical.  Intelligent people have been claiming the benign environmental nature of chemically preserved wood for over 50 years – including products using creosote, penta, and CCA – and each of these products lead to superfund clean-up sites.  So the industry’s record is not good in terms of understanding the nature or risk of these kinds of products.  I still remember a conversation I had back in the late 1980’s with a professor at a well know university, as he confidently espoused the benefits of the product since the materials were permanently chemically bonded to the wood.  I asked “IF the chemicals are permanently bonded, why is there only a 50 year guarantee, and why does wood appear to eventually rot?"  He didn’t have an answer.  ACQ has not been without its problems either.  As CEO of a company that has sold a lot of ACQ, I know the devil’s in the details and there is a LOT of ACQ product in place without appropriately protected fastening systems.  Any product that needs “special” fasteners - different than are historically the case -  is a challenge.  It doesn’t mean it can’t work – it just means it is potentially problematic.  I do not have enough detail about the new osmose product to have an opinion at the moment but, the test is: are you required to where gloves and a mask when working with the product?  In general, and in my experience, IF it is toxic to work with it becomes toxic to the environment.

    - Doc


    The important thing is that

    The important thing is that whatever you consider to be green should last longer without emitting harmful chemicals or they will cause as serious problem. The reason why say vinyl fences are considered to be green is because it can be made from recycled materials but if they don't last then what's the point.

    Add new comment
  • Valerie asked

    ON September 17th, 2009 AT 1:43 PM

    I would like to heat my home with wood or at least supplement with wood. What are some of the better wood stoves that burn more efficiently? I heat with natural gas now but prices are rising. thank you - Val


    ON October 2nd, 2009 AT 1:43 PM

    Hi, I am personally a huge advocate of what are generally described as Russian or Finnish Fireplaces (see Tulikivi fireplaces on the web), generally large masonry masses that heat from very hot fires for brief time periods time (e.g., 1-2 hours) and then radiate from that mass for extended periods (e.g., 24 hours). However, although they are wonderful, and I have had three, they also tend to be quite expensive.  For specific information on individual wood burning stoves I would recommend  www.metaefficient.com or www.hearth.com as good sources of information and comparisons... - Doc

    Add new comment
  • Julia in Maine asked

    ON September 10th, 2009 AT 9:44 AM

    What kind of FSC wood is available in California? Where is it milled? What products does it go into? Where is it sold? Is it kiln dried?


    ON September 17th, 2009 AT 9:44 AM

    For information about FSC available products, you can search the following databases and websites:


    This site will allow you to search for FSC certificate holders by state and shows about 460 companies in California:



    For more information about a specific company and the products they produce, you can click on the name of the company in the listing or search this database for additional details about the company you are interested in:



    This database can also be searched by product and should be able to answer your questions!

    Add new comment
  • Marc of Minneapolis asked

    ON September 17th, 2009 AT 9:38 AM

    If we reduce the consumption of 2x10 and larger dimensional lumber is it true that we will be helping to promote more healthy old growth forests, which have biodiversity and carbon sequestering benefits?


    ON September 17th, 2009 AT 9:38 AM

    First, hands-down, the lowest impact structural material available (as determined by rigorous environmental life cycle analysis) is solid sawn lumber.  Second, a 2x 10 can be produced from a 12 inch diameter (dbh) log.  A 16-18 inch diameter log will yield many 2x10s.  Logs of that diameter are commonly produced from trees 25-30 years of age (Southeastern U.S.), 40-80 years of age (Pacific Northwest), 60-100 years of age (Northeastern  U.S. and Canada).  None of these age categories fit the common definitions of old growth (e.g., in the Lake States region old-growth forest is frequently defined as greater than 120 years of age).


    The question of whether prohibiting use of solid lumber of large size will promote a greater number of large, old trees is interesting.  About 60% of dimensional lumber used in the United States comes from privately owned forest lands in the United States .  Prohibition of the use of solid lumber and encouragement of the use of composite lumber (both of which are increasingly encouraged in green building standards) is sending the wrong message to landowners and forest managers. The promotion of composite materials over solid wood discourages woodland owners from making the commitments (and taking on the costs and risks) that go with growing trees for very long time periods before harvesting (e.g., 25 to 100 years depending on the region and species). Instead, the composite market signals encourage landowners to grow trees over very short rotations (e.g., less than 30 years), harvest them when small, and feed the growing composite products market that has become so trendy.  In extreme cases, the message landowners may be getting is to make sure to avoid allowing trees to become large and old enough that they will be viewed as "candidate old growth" and then subject to potential reserve status or protection that would limit the landowner’s opportunities to receive financial benefit from their decades long commitment to land stewardship.


    The bottom line is that wood is a green product and using wood products encourages the continuation of working forests across the landscape. Using larger dimensional lumber specifically encourages the management of forests to produce this type of product which generally takes more time and asks for an expanded commitment from the landowner.  An effective way to reward woodland owners’ commitments to land stewardship and to encourage a continuation of that commitment is to value all of the products and services that forests provide, including recreation and scenic beauty, as well as wood and fiber as raw materials for our buildings and economy.

    Add new comment
  • Jean Buckley asked

    ON June 21st, 2009 AT 2:49 PM

    I am putting an addition on my 1921 bungelow and trying to go green. I heard a woman speak about the green star program and they suggest using non added formeldyde plywood but I can't find it. Do you know where you can purchase it or what where you would get the most environmentally friendly wood? Also I was at the Natural Built Home store on Minnehaha and they told me marmoleum can be used with in floor heating but the gypcrete has to be guaranteed and i don't know where you would get that or how it would be guaranteed? As Kermit says, "It is hard to be green" sometimes. Thanks, Jean


    ON June 23rd, 2009 AT 2:49 PM

    Jean: Thanks for your questions!  First – environmentally friendly lumber is available at most building materials stores these days, you just need to be patient because not all staff at all locations are familiar with the types of question you ask, although they are increasingly well informed.  Based on your comments about Minnehaha street I assume you are in the Minneapolis, MN area -  and there are a couple of very good building material suppliers there.  I would suggest either “The Remodeler’s Choice” on 28th Street in Uptown Minneapolis or “Shaw-Stewart Lumber” on Johnson Street as good choices.  Both are Forest Stewardship Council (FSC) chain-of-custody certified to provide FSC wood products and both should be reasonably familiar with your issues.  Second, as for your question about marmoleum over gypcrete, the issue is the gypcrete is so absorbent that there is the possibility that the adhesive used on the marmoleum will not adhere well, or that there will be adherence issues over time.  That is why some people are reluctant to put those kinds of flooring products over the gypcrete.  To help address this, gypcrete requires a sealer prior to using an adhesive.  In addition, materials requiring special adhesives (e.g. Marmoleum due to the linseed oil in the product) must use the procedures specified by that product (e.g. Marmoleum).  In other words, neither party is likely to guarantee it.  Hope this helps, and your marmoleum dealer should be able to more specifically clarify their requirements for you (exact adhesive and the like), including use with gypcrete which I assume they would have significant experience with.  - Doc

    Add new comment