As the name implies, solid hardwood is solid wood, all the way through. Engineered hardwood flooring is done in layers. The top layer is a hardwood veneer and then beneath that, there are layers (or plies) of wood. Generally, these plies are perpendicular in direction and laminated together (similar to plywood), and generally (but not always), these plies are made of wood although they are not necessarily the same species as the top layer.
Engineered wood is a layered product made of an actual but thin slice of hardwood on top of a base of high-quality plywood.
Solid hardwood and nothing but hardwood, a homogeneous product from top to bottom and side to side.
Thickness can range from 3/8-inch to 1/2-inch. Standard widths are 3 1/4-inch, with plank sizes starting at 5 inches wide.
Thickness typically is 3/4-inch. The standard width begins at 2 1/4 inches wide. Plank width begins at 5 inches and can go up to 11 inches wide.
Pre-finished vs. Site-finished
Most engineered wood floors are pre-finished, though some companies do make site-finished engineered wood flooring.
Pre-finished is increasingly the finish of choice for solid wood floors. Site-finished (also called unfinished) accounts for about 25-percent of solid hardwoods today.
Sanding is one of the greatest differences between engineered and solid wood flooring. Engineered wood can be sanded but only once or twice lightly, before the thin upper layer wears away.
Solid wood can be sanded numerous times. Eventually, solid hardwood will become too thin after years of sanding, compromising its structural integrity.
Engineered wood is easier than solid hardwood as you have a greater range of installation methods, including stapling or nailing, fold-and-lock, or glue.
Solid wood flooring is nailed or stapled down. It is never installed on a floating basis.
Because engineered wood floors are real wood, they can be advertised as such in real estate marketing materials, making them more attractive to buyers.
As long as the floor is in good shape, it is on equal terms with engineered wood flooring in terms of resale value.
Engineered wood floors are durable, but not comparable to solid wood. Because the surface is thin, it can become chipped or de-laminated if stressed beyond normal conditions. Yet its ability to hold up to limited moisture helps bring up its durability rating.
Well-maintained solid hardwood flooring will last for decades. Moisture is the enemy of this organic product. Wood floors do stand a chance of being salvaged after flooding, but they will never perfectly return to their former shape.
Engineered wood is better than solid hardwood at dealing with moisture. Its plywood base is dimensionally stable, meaning that it warps and flexes less easily upon contact with moisture than solid wood. Fibers in plywood run in cross-wise layers, a far more stable structure than solid wood's parallel fibers.
Solid hardwood is never recommended for bathrooms, basements, or other areas where moisture is prevalent or even expected. Still, solid hardwood can resist some moisture. Site-finished wood flooring (as opposed to pre-finished), though, does have a sealed top layer that can shed some moisture.
Hard hardwoods are the most durable, including many of the South American or Indonesian exotics, as well as birch, maple, and walnut. Soft hardwoods such as pine will not be found in engineered wood format.
Solid hardwood encompasses a greater range of wood hardness than engineered wood. Hardness ranges from extremely soft and appropriate only for utility areas (such as Douglas Fir for workshops) to extremely tough hardwoods (for example, Brazilian Walnut).