Engineered flooring, due to the way it is manufactured, offers superior dimensional stability. It is more stable than its traditional counterpart, “solid” wood flooring. If you are unfamiliar with the construction of engineered wood flooring, it is essentially manufactured in a manner similar to plywood. The plywood base, or “substrate,” is made of thin layers of wood which are oriented with their grain in an alternating arrangement (90 degrees for each subsequent layer, or “ply”), and glued under heat and pressure. This creates a very stable wood flooring product, less susceptible to movement that could present itself as gaps between flooring boards, cupping, or crowning.
This highly stable base, when bonded to the top layer, or “wear layer” (what you walk on and see after installation), is what makes engineered wood flooring more resistant to the normal movement that occurs in wood flooring during changes in the relative humidity within the structure.
Many homes and commercial buildings undergo significant seasonal variations in relative humidity. In some parts of the United States the relative humidity within a building could range from 10% in the winter to 90% in the summer, depending on whether humidification is used during the heating months, and whether air conditioning (which dehumidifies the air) is used in the summer months.
All wood “moves” to a certain degree with these changes in relative humidity, and engineered wood flooring simply moves less than solid wood flooring because of the superior dimensional stability of the multi-ply substrate. Today there are a myriad of choices in engineered flooring in both exotic and domestic species, in both prefinished as well as unfinished engineered wood flooring. For many installation scenarios the superior dimensional stability of engineered wood flooring is worth considering.