Masonry vs. Zero Clearance
Masonry material has been a fireplace method for centuries. Anything that must be mortared together is considered masonry. Since they are built by hand, no two masonry fireplaces are exactly alike.
While brick and ceramic are the most common materials used for the internal, or working, components of a masonry fireplace, the face material can also include stone, marble, granite, travertine and tile.
Zero Clearance (or ZC) fireplaces are pre-manufactured metal fireboxes with coinciding metal flue pipe. Some are obvious to spot with metal louvers on the top and bottom. Other ‘Clean Faced’ units require a bit more inspection.
ZC fireboxes have a manufacturer and model number associated with each unit. Most have this information mounted somewhere near the front of the firebox and can be referenced to easily purchase doors.