Levels of Quality, Sizes, Edges, and Joining Systems. Shaw classifies its floors as Good, Better, Best, and Superior. Most floors fall in the Better or Best categories, with some floors falling into both categories at once (doubling the wear layer thickness bumps a product up to the Best level).
If your shelf projects 1 1/2 inches or less, there must be at least six inches between the top of the fireplace and the mantel. Any parts of the mantel that project more than 1 1/2 inches must be at least 12 inches from the top of the fireplace.
The mantle under the crust is about 1,800 miles deep (2,890 km). It is composed mostly of silicate rocks rich in magnesium and iron. Intense heat causes the rocks to rise. They then cool and sink back down to the core. This convection â like a lava lamp â is believed to be what causes the tectonic plates to move.