Wood Flooring – Lawsuits, Experience, and Opinions

Photo courtesy of Gene Mall

I love solid wood floors.  I have seen old dilapidated houses bought with a credit card and the floors and paneling salvaged and resold for a tremendous profit.   Studies have shown that patients in hospitals will heal faster when they are in a room with a more natural “feel” than a traditional hospital room.  Part of this natural feel is wood floors (and paneling too).  Wood has an inherent beauty and nostalgic affect, and I think most people appreciate it and enjoy it especially during these complex and busy days we all tend to live.

Wood floors can have problems.  Typically, if you have a wood floor problem, you have a wood moisture content problem.  Each piece of wood is unique and depending on how the piece was sawn will determine if most of the dimensional change is in the thickness or width of the plank.  The most frequent problem is buckling of the floor or excessive gaps between the planks.  Buckling will occur when the moisture content of the boards is significantly increased after the floor is installed.  The boards want to swell but are restrained by adjacent boards and/or mastic and instead will buckle.  This can be due to several factors such as a water leak in the house, poor vapor barrier below the house if the house is on stilts, or failure to acclimate the wood to the equilibrium moisture content of the house before installation.   In my experience, failure to acclimate the wood is often the culprit.  I recall a case years ago in which a homeowner purchased custom wood flooring from a local distributor.  The wood had been kiln dried to 6-8% MC so it was deemed by the installer that acclimation was not necessary.  However, the boards had sat in a non-climate controlled shed for years after they were kiln dried.  I determined that the moisture content of the boards at the time of installation was probably around 18% and gradually decreased to 8% once in service.  This explains why large gaps were appearing between the boards. 

As a home owner, you may be wondering what can you do to prevent wood flooring problems.  I suggest you purchase a moisture meter and randomly check a few of the boards before installation.  It will take you seconds but can potentially save you hours of heart ache down the road.

Shell Rot in Wood Poles

Photo courtesy of Osmose Utilities

All preservative-treated wood poles commonly used in North America are subject to “shell rot” or surface decay below the ground line.  In southern pine poles, which compose roughly 85% of the poles in North America, this type of decay is most common.  Western species such as Douglas-fir and cedar are less susceptible to surface decay.  However; however, only the heartwood of these species are naturally decay resistance.  So, sapwood of neither Douglas fir nor western red cedar is naturally resistant to decay.  Therefore, as these poles age they can be subject to surface decay, though at later stages in life when compared to southern pine.

Wood destroying decay fungi are the most common wood-destroying organisms and they can be found in virtually any environment.  Decay fungi require four elements in order to live and attack wood: air, water, a favorable temperature, and food (in this case, the wood pole).  If you can remove any of these factors, then the fungi cannot live.  These four elements are most prevalent from the groundline to 18 inches below the groundline.   Beyond this depth, the soil becomes more anaerobic and oxygen is limited.  For any wood product, plywood, lumber, etc, the surface of the product has a tremendous effect on the strength.  For poles, the outer two to three inches governs approximately 90% of the strength.  Therefore, it is critical to inspect and protect this part of the pole to preserve the pole’s strength.  I have served as an expert witness on many cases in which a pole has fallen and caused property damage or death and most could be prevented by (1) having a pole inspection program and (2) using remedial preservative treatments at the groundline when an initial problem is detected.

Extending the life of a pole can be accomplished by in-place treatment with remedial preservatives.  In Bulletin 1730B-121, the Rural Utilities Service (RUS) recommends an 8 to 12 year cycle based on the decay conditions of the particular environment where the poles are installed.  Excluding remedial treatments from a pole maintenance program leaves owners with an inspection only program.  This “run to failure” strategy can have significant long-term negative impacts on our natural resources, skilled manpower, financial resources, and it increases the pole owner’s risk with regard to safety and reliability (Osmose 2017).

Externally applied preservatives vary greatly in their active ingredients, environmental profile, efficacy, penetration into a pole, and their ability to remain in the treatment zone so as to control decay for an extended period of time. Selecting an appropriate remedial treatment strategy can save pole owner’s millions of dollars by reducing the number of pole change-outs and reducing the risks associated with pole failures.  Most remedial treatments are applied by brush as a paste or as a bandage, similar to a large band-aid wrapped around the groundline.  The table below is from Freeman (2007).

References:

Freeman, H.M. 2007.  Wood Pole and Crossarm Maintenance and Remedial Treatment:  A State of the Industry Review.  In:  Proceedings of American Wood Protection Association. 103:151-177.  Birmingham, AL.

Osmose.  2017.  http://www.osmose.com/newsletter-2017-q4-restore-not-replace

The Importance of Wood Species Identification

A hand lens is essential to see anatomical properties.

One of the first things you need to understand about wood is variability.  As a biological material it is inherently different than other building products such as steel.  A steel beam has uniform properties throughout the beam and each beam will have essentially the same properties.  A wood beam will not.  Wood properties vary from tree to tree but also within a tree!  For an individual tree, there is a vertical and horizontal profile that corresponds to tree growth in both the vertical (longitudinal direction) and diameter (radial direction).  These changes are most profound in pine trees.  So, this is the reason why when you go to your local lumber yard you have to dig around in the bin to find the board(s) that you want.  They all have the same grade but due to variability they don’t all look the same nor will they all perform the same. 

Species has a great influence on wood properties.  Each species has unique anatomical properties that allow for a trained eye to properly identify the species.  There are a few exceptions.  For example, there are several species that are classified as southern pine.   Botanically a forester can identify these as separate species based on the cones and needles.  However, there is insufficient variation in the wood properties to separate them so they are all sold commercially as southern yellow pine (SYP). 

The main factor that separates wood species is density which is simply mass per unit volume.  Due to anatomical structure, some species have a higher density (oak, hickory) than others (cottonwood, walnut).  You may wonder if they have the same volume, why isn’t the density the same?  Why does the weight vary between species if we take measurements at the same moisture content?  Again, due to the inherent anatomical structure of some species they have a greater amount of wood per unit volume and others have a greater amount of air per unit volume.  If you were to look at an oak species under a microscope you would see thick cell walls with little open spaces (air).   The opposite is true for a low density species.   So, the first step to proper wood utilization is wood species identification.  If you need help with wood species identification for a special project, legal matter, etc., please contact me at tfshupe@gmail.com.