White Oak (Quercus alba) is a highly regarded hardwood native to eastern North America. It is a popular choice for high-end furniture, flooring, and outdoor applications like boat building due to its strength, durability, and resistance to decay. White Oak is also the traditional material for barrels used to age whiskey and wine. When considering White Oak for any project, its weight is not constant; it is a variable measure directly tied to its density. Density is the most reliable metric for predicting the weight of a given volume of wood, but this value shifts significantly based on the amount of water held within the wood’s structure.
How Moisture Content Affects Weight
The weight fluctuation in White Oak is primarily driven by its moisture content (MC), which is the weight of water present compared to the wood’s oven-dry weight. Freshly cut wood, known as “green” wood, is at its maximum weight because the cells are saturated with water. The green weight of White Oak can be over \(30\%\) heavier than its dry weight.
As wood dries, it loses this free water until it reaches the Fiber Saturation Point (FSP), where the cell walls remain saturated but the wood has not yet begun to shrink. For commercial purposes, wood is categorized into three states: green, air-dried, and kiln-dried. Air-dried wood is seasoned outdoors until it reaches an equilibrium moisture content of \(12\%\) to \(20\%\). Kiln-dried wood, the standard for indoor use, is mechanically dried to a stable moisture content, typically between \(6\%\) and \(8\%\).
Standard Density Measurements of White Oak
The standardized way to quantify White Oak’s bulk is through its density at a specific moisture content, measured in pounds per cubic foot (lbs/ft\(^3\)). The industry standard reference for White Oak density is \(47\) lbs per cubic foot at \(12\%\) moisture content. This figure is used for most construction and woodworking calculations.
In comparison, freshly harvested, or green, White Oak has a density that averages around \(62\) lbs per cubic foot. The wood’s specific gravity (SG) also characterizes its density by representing the ratio of the wood’s density to the density of water. White Oak has an SG of approximately \(0.75\) at \(12\%\) MC, meaning it is \(75\%\) as dense as water and will float.
Calculating the Weight of Common Volumes
Translating density into practical volumes provides useful estimates for consumers and woodworkers.
Board Foot (BF)
The board foot (BF) is a common unit for measuring rough lumber, defined as a piece one inch thick, twelve inches wide, and twelve inches long, equating to \(1/12\) of a cubic foot. Based on the standardized density of \(47\) lbs/ft\(^3\) at \(12\%\) MC, one board foot of White Oak weighs approximately \(3.9\) pounds.
Cord
The cord is the traditional measurement for stacked firewood, defined as \(128\) cubic feet of stacked wood. Since a cord includes air space, the actual volume of solid wood is closer to \(85\) cubic feet. A cord of seasoned White Oak (at about \(12\%\) MC) typically weighs between \(3,500\) and \(4,200\) pounds. A cord of green White Oak, due to its higher moisture content, can weigh substantially more, often ranging from \(5,200\) to \(5,600\) pounds.