Tips for Building a Modular Fireplace
1. Build it on reinforced concrete or structurally engineered foundation.
2. For raised hearth, build base of concrete block.
3. Assemble modular firebox and chimney on top of hearth, gluing together components with manufacturer’s mortar.
4. Scratch coat interior with ¼-inch knotch trowel.
5. Line firebox with firebrick at least 1 1/8 inch thick; use firebrick or refractory mortar.
6. Finish exterior with plaster, brick, stone, or stucco.
7. Start with small fires to cure mortar and reduce moisture in units.
Build a modular fireplace to extend your outdoor living space into cooler weather.
Raised hearth can double as bench.
Components fit together like a puzzle; each one goes into only one place.
To make firebrick adhere better, sponge down firebox and dip brick into water just before mortaring.
Keep application ¼ in thick or less so mortar won’t shrink in heat.
Apply lathe and scratch coat first.