Compressed board is generally heavier than solid wood. This is due to the manufacturing process of compressed board, which involves bonding multiple layers of wood together under high pressure and heat. The density of compressed board is typically higher than that of solid wood, resulting in a greater weight per unit volume.

The density of solid wood varies depending on the type of wood, but it generally ranges from 0.4 to 0.9 grams per cubic centimeter (g/cm³). In contrast, compressed board, also known as particleboard or medium-density fiberboard (MDF), has a higher density, typically ranging from 0.6 to 1.2 g/cm³. For example, MDF has a density of around 0.8 g/cm³, which is significantly higher than the density of most solid woods.

According to the American Hardwood Export Council, the average density of solid wood is around 0.6 g/cm³, while the density of MDF is around 0.8 g/cm³. This difference in density directly translates to a difference in weight. For instance, a 1-meter cube of MDF would weigh approximately 800 kilograms, whereas a 1-meter cube of solid wood with a density of 0.6 g/cm³ would weigh only about 600 kilograms.

Additionally, the manufacturing process of compressed board contributes to its weight. The high pressure and heat used to bond the wood fibers together create a dense, solid material that is heavier than the original wood components. This densification process also makes compressed board more stable and less prone to warping or splitting, which can be beneficial for certain applications.

In conclusion, compressed board is heavier than solid wood due to its higher density and the manufacturing process that bonds multiple layers of wood together. This increased weight offers advantages in terms of stability and durability, but it also makes compressed board less suitable for applications where weight is a critical factor.