solid core

Definitions

Construction

  • The inner layers of a plywood panel that contain no open irregularities, such as gaps or open knotholes, and in which the grain runs perpendicular to the outer plies. Solid core is primarily used as underlayment for resilient floor covering.
  • A flush door, used in entries and as fire-resistant doors in which particleboard or wood blocks completely fill the area between the door skins.
http://www.dictionarycentral.com/definition/solid-core.html