Solid wood is milled from a single 3/4"-thick piece of hardwood. Because of its thickness, a solid hardwood floor can be sanded and refinished over several generations of use. Solid wood flooring expands and contracts with changes in your home's relative humidity. Normally, installers compensate for this movement by leaving an expansion gap between the floor and the wall. Base molding or quarter-round is traditionally used to hide the extra space.
Engineered wood is produced with three to five layers of hardwood. Each layer is stacked in a cross-grain configuration and bonded together under heat and pressure. As a result, engineered wood flooring is less likely to be affected by changes in humidity and can be installed at all levels of the home.
Your hardwood floor will be in one of three locations:
If you plan to install over concrete, you must use an engineered product to ensure structural integrity. Solid wood flooring or engineered flooring may be used over plywood, wood, or OSB subfloors.
If so, you'll want to select an engineered hardwood. The moisture resistance of an engineered hardwood makes it suitable for rooms where the presence of moisture is possible, such as bathrooms.
Provided by shawfloors.com