ZERO With masons becoming harder to find, many builders are turning to factory-built, or prefabricated, fireplaces and chimneys, These new technologies have made the installation of fireplaces easy enough for even a novice builder. Factory-built fireplaces have been in use for over 25 years now, and most have stood the test of time. They have been modified in recent years to improve some of their basic components, but in general their basic design has stayed the same. Each factory-built fireplace consists of a fireplace unit and a chimney system. It comes Preassembled The fireplace unit comes complete with a firebox, damper and smoke chamber, all preassembled. The units come in various sizes, and some manufacturers have