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.
In most instances, its very easy to determine the correct size mantel for your fireplace as fireplaces generally come in two sizes. If you have a 36 fireplace - the inside width of your mantel should be 48.