Longstrip hardwood floors are very similar to engineered hardwood floors, for they consist of several layers of wooden plies glued to one another, much like engineered hardwood floors. The core of the wood is a softer material, and incorporates the tongue and groove system. On the top of the core, a hardwood finish layer is attached and underneath the core, a soft wood ply is glued. Longstrip hardwood floors differ from engineered hardwood floors due to the fact that they have longer and wider planks. Usually, longstrip planks are 86 inches long, and 7 ½ inches wide. The top layer of the plank has about two or three rows of hardwood strips attached together to form a solid surface, which makes the entire plank look as though it consists of two or three planks attached together. The surface of the plank is actually made up of smaller hardwood pieces that are attached together in three rows. This is called the 3-strip design, but there are also 1 strip designs, where the entire board looks like one wide plank. Longstrip hardwood floors are usually installed using the floating procedure, but they can also be glued down or nailed down with staples. Unlike solid hardwood floors, longstrip wood floors can be installed above or below ground level. They are not sensitive to humidity like solid hardwood floors are, so they are convenient in almost any location, regardless of changes in weather or moisture. They are available in numerous species and colors, and are just as beautiful in appearance as any of the other types of hardwood floors.