The moisture within timber that is contained in the cells walls.

The moisture within timber that is contained in the cells walls.

• A. Drying in a kiln
• B. Air-drying alternatives
• C. Sun drying
• D. Absorbed moisture

Answer: (D)

Moisture in timber exists in two forms: free water in the cell cavities and moisture that is bound to the cell walls. The description “moisture within the cells walls” refers to absorbed moisture, because this water is chemically bound to the wood’s cell-wall polymers like cellulose and lignin. It forms hydrogen bonds and behaves differently from free water, being harder to remove and staying tied to the wood as it equilibrates with environmental humidity. The other options describe methods to remove moisture (drying in a kiln, air-drying, sun drying), not the form of moisture inside the wood.

Moisture in timber exists in two forms: free water in the cell cavities and moisture that is bound to the cell walls. The description “moisture within the cells walls” refers to absorbed moisture, because this water is chemically bound to the wood’s cell-wall polymers like cellulose and lignin. It forms hydrogen bonds and behaves differently from free water, being harder to remove and staying tied to the wood as it equilibrates with environmental humidity. The other options describe methods to remove moisture (drying in a kiln, air-drying, sun drying), not the form of moisture inside the wood.