A Century Apart: Comparing 2×4 Lumber from 1918 and 2018

Lumber 2x4


Lumber is a fundamental building material that has undergone significant changes over the past century. The way we source, harvest, and process wood has evolved to meet the growing demands of our modern world. In this article, we’ll delve into a fascinating comparison between 2×4 lumber from 1918 and 2018, highlighting the key differences in their growth patterns, density, strength, combustion properties, and resistance to pests and decay.

The Old Growth Lumber of 1918:

In 1918, the 2×4 lumber was primarily sourced from old-growth forests. These ancient woodlands featured towering trees that had matured over centuries, resulting in lumber with unique qualities. Old-growth lumber often boasted around 60 rings per inch, signifying the tree’s age and slow growth rate. This slow growth led to a denser, stronger, and more resilient wood.

  1. Density and Strength: Old-growth lumber was renowned for its exceptional density and strength. The slow growth allowed the tree to develop tightly packed rings, creating wood that was more resistant to wear and tear. This made it ideal for load-bearing structures and long-lasting applications.
  2. Combustion Properties: Old-growth lumber burned at a slower rate compared to its modern counterpart. The dense wood and fewer air pockets made it less susceptible to ignition, contributing to its fire-resistant qualities.
  3. Insect Resistance: The density of old-growth wood also made it naturally resistant to pests and insects. Its tighter grain patterns provided fewer entry points for wood-boring insects, making it a preferred choice for outdoor and structural use.

The New Growth Lumber of 2018:

In stark contrast, the 2×4 lumber from 2018 was predominantly sourced from newer growth forests. These forests were cultivated with the sole purpose of timber production, leading to a dramatically different growth pattern.

  1. Growth Rings: New-growth lumber typically had around 16 rings per inch, signifying a significantly faster growth rate compared to old-growth trees. This faster growth resulted in lighter and less dense wood.
  2. Density and Strength: Due to the faster growth, the wood was less dense and subsequently less strong compared to old-growth lumber. While it is still suitable for many construction applications, it may not withstand heavy loads or extreme conditions as effectively.
  3. Combustion Properties: New-growth lumber burned more readily than old-growth wood. Its lower density and higher air content made it less fire-resistant, requiring additional fireproofing measures in certain applications.
  4. Insect Resistance: The wood from newer growth forests was more susceptible to pests and insects. The lighter, less dense composition provided easier access points for wood-boring insects, necessitating regular maintenance and protective treatments.


The comparison between 2×4 lumber from 1918 and 2018 showcases the significant impact of changing forestry practices and wood sourcing on the quality and properties of the final product. While the old-growth lumber of 1918 offered denser, stronger, and more resistant wood, the newer growth lumber of 2018, originating from managed forests, was lighter, less dense, and more susceptible to environmental factors.

These differences are a reminder of the value of sustainable forestry practices and the need to balance timber production with the preservation of old-growth forests, which provide wood with unique and valuable characteristics. In the construction industry, understanding these distinctions allows for informed choices that align with the requirements of specific projects and contribute to the responsible use of our natural resources.