The Difference Between Masonry and Zero Clearance (ZC) Fireplaces

Masonry Fireplaces

• Masonry fireplaces insulate the walls and frame of your home with thick layers of stone or brick. This type of fireplace is built partially or completely within the frame of the home. These fireplaces consist of a firebox, throat and chimney. The firebox is a chamber made of firebrick that contains the fire. The firebox is open to the interior of the home. Smoke from the firebox is drawn into the throat, which connects the firebox and chimney. A damper controls the amount of air flowing into the chimney.

Zero Clearance Fireplaces

• Zero clearance fireplaces are designed to work inside wood-framed walls in close proximity to flammable materials. The firebox of a zero clearance chimney uses firebrick surrounded with a double-walled metal box that creates a pocket of insulating air. Zero clearance fireplaces have a forced air system with fans to vent the warm air from around the fireplace into your home. Smoke from the firebox is vented through an insulated vertical pipe that connects directly to the firebox.

Benefits

• Zero clearance fireplaces are lighter, more compact and less expensive than masonry fireplaces. You can install zero clearance fireplaces in your home without needing to install a concrete footer and masonry chimney on the outside of your home. Zero clearance fireplaces can use either wood or gas fuel sources, while masonry fireplaces are typically designed only for solid fuel. Zero clearance models can substitute the large, outer hearth used in masonry fireplaces with glass doors to prevent flaming debris from damaging your floors.

Considerations

• Zero clearance fireplaces are lighter than masonry fireplaces, but they still need structural reinforcement. Most zero clearance fireplaces require doubled floor joists to support the firebox and concrete blocks to support the chimney. Masonry fireplaces need a solid concrete footer to support the fireplace and the chimney. Open masonry fireplaces also must have a substantial hearth in front of the firebox to prevent embers from damaging the floor. While zero clearance fireplaces with a forced air system will heat your home more effectively than an open masonry fireplace, you can install a fireplace insert in an existing masonry fireplace to get the same benefits as the zero clearance system.