Start by confirming whether you have a masonry or a prefabricated (factory-built) fireplace — this determines door compatibility and safety.
Masonry Fireplace
- Built from brick/stone; real brick firebox.
- Usually has a full masonry chimney.
- Supports heavy-duty doors; ceramic glass is an option.
Prefab (Zero-Clearance)
- Factory-built metal firebox with a metal chimney pipe.
- Often has a manufacturer label/tag behind louvers or inside the frame.
- Typically uses tempered glass doors.
Tip: If you see a metal ID tag or a metal chimney pipe, you have a prefab (factory-built) fireplace.
If the firebox is made of brick and the chimney is full masonry, you have a masonry fireplace.