Red Birch and Yellow Birch are from the same tree. The yellow is the sapwood (outer portion of the log), and the red comes from the heartwood (the center of the log). Red Birch is dearer and is always more expensive, since the log yields much less of it than Yellow Birch. “Premium” grade denotes the highest grade currently available in prefinished Red Birch flooring. This is a solid floor milled with microbevels and a smooth surface. It’s suitable for above grade installations, and can be nailed, or glued with the appropriate mastic. The finish has a limited 50-year residential warranty. The supply is limited at these prices!