Which type of lumber is typically more susceptible to warping?

Unseasoned lumber is typically more susceptible to warping because it contains a higher moisture content than seasoned lumber. When unseasoned lumber is exposed to changes in humidity and temperature, the excess moisture can cause the wood to expand and contract unevenly as it dries out. This process can lead to warping, cupping, or twisting of the wood as it acclimates to its environment.

In contrast, pressure-treated lumber undergoes a treatment process that helps protect it from decay and insects, which may also enhance its dimensional stability. Engineered lumber is designed to be more stable through its manufacturing process, reducing the likelihood of warping. Prefinished lumber, which has a protective finish applied before use, also maintains its shape better during changes in environmental conditions. Thus, unseasoned lumber stands out as the most likely candidate to warp due to its inherent moisture issues.