Seasoning of timber in building construction: what is the fundamental purpose of seasoning before use? (Select the objective that directly addresses moisture-related dimensional stability and durability.)

Introduction / Context:
Freshly felled wood contains a significant amount of water that leads to shrinkage, warping, fungal growth, and poor finish. Seasoning is the controlled process of reducing moisture to levels suitable for service. The key goal is moisture reduction, which secondarily improves strength and workability.

Given Data / Assumptions:

• Green timber has high free and bound water.
• Moisture reduction enhances stability and resistance to decay.
• Seasoning methods include air and kiln seasoning.

Concept / Approach:
By driving off free and bound water to near the equilibrium moisture content of the installation environment, timber dimensional changes are minimized in service. Although strength increases as moisture drops, that increase is a consequence of drying rather than the primary goal stated in specifications.

Step-by-Step Solution:

Verification / Alternative check:
Joinery standards specify moisture ranges (e.g., 8–12% for interiors) precisely to prevent in-service movement and defects.

Why Other Options Are Wrong:

• Increasing moisture: opposite of the requirement.
• Increasing strength directly: strength improvement is secondary to drying; the process target is moisture reduction.
• None of these: incorrect since moisture reduction is correct.

Common Pitfalls:
Over-rapid kiln schedules causing case-hardening; ignoring acclimatization; using unseasoned timber for fine joinery resulting in post-installation warping.

Final Answer:
Decreasing moisture content