As you walk or drive through Nellie Gail Ranch, you may notice some of the wood fencing materials along the trail system have different colors. All of Nellie Gail Ranch’s trail fencing, which totals approximately 11 miles, is made of pressure treated pine lumber. Pressure treated wood is widely used for outdoor construction projects because of how well it resists the elements. The lumber is treated under high vacuum pressure that forces chemical wood preservatives into the fibers of the wood. The color of pressure treated lumber depends on the chemical that was used during the pressure treatment process.
GREEN (Discontinued Product)
Chemical used – Chromated Copper Arsenate
The most common preservative used to pressure-treat lumber when Nellie Gail Ranch was first developed was chromated copper arsenate. However, due to its harsh chemical properties, the U.S. Environmental Protection Agency banned the use of this type of lumber for residential use in 2004. Nellie Gail Ranch stopped purchasing this type of treated wood six years earlier around 1998.
BROWN (Currently Used)
Chemical used – Copper Azole
Copper azole mixtures, which combine copper with a fungicide from the -azole (nitrogen ring-based) chemical group, are considered a safe and effective replacement for chromated copper arsenate. Wood treated with copper azole mixtures is light brown when new, but its color fades to a silver-gray as the wood ages.
In this photo taken on one of our trails, you can see the lighter green (almost white) board which is an old piece of fencing that was used as a patch. The brown boards pictured are new treated lumber patches and the predominant color you see, dark brown/silver-gray is the aged brown treated wood. In a few years, the newer brown patches will match the older fencing color as it fades.
To efficiently use Nellie Gail Ranch resources we try to balance when we should replace full sections of fencing and when repairs should be performed to extend the overall life of the fencing. This does result in some fence color variations that take some time to fade together.