International Building Code Section 2112


International Building Code 2112.1

Definition.Amasonry heater is a heating appliance constructed
of concrete or solid masonry, hereinafter referred to as
“masonry,” which is designed to absorb and store heat from a
solid fuel fire built in the firebox by routing the exhaust gases
through internal heat exchange channels in which the flow path
downstream of the firebox may include flow in a horizontal or
downward direction before entering the chimney and which
delivers heat by radiation from the masonry surface of the heater.

International Building Code 2112.2

Installation. Masonry heaters shall be installed in accordance
with this section and comply with one of the following:
1. Masonry heaters shall comply with the requirements of
ASTM E 1602; or
2. Masonry heaters shall be listed and labeled in accordance
with UL 1482 and installed in accordance with the
manufacturer’s installation instructions.

International Building Code 2112.3

Footings and foundation. The firebox floor of a
masonry heater shall be a minimum thickness of 4 inches (102
mm) of noncombustible material and be supported on a
noncombustible footing and foundation in accordance with
Section 2113.2.

International Building Code 2112.4

Seismic reinforcing. In Seismic Design Category D, E
and F, masonry heaters shall be anchored to the masonry foundation
in accordance with Section 2113.3. Seismic reinforcing
shall not be required within the body of a masonry heater with a
height that is equal to or less than 3.5 times its body width and
where the masonry chimney serving the heater is not supported
by the body of the heater. Where the masonry chimney shares a
common wall with the facing of the masonry heater, the chimney
portion of the structure shall be reinforced in accordance
with Section 2113.

International Building Code 2112.5

Masonry heater clearance. Combustible materials
shall not be placed within 36 inches (765 mm) of the outside
surface of a masonry heater in accordance with NFPA 211,
Section 8-7 (clearances for solid fuel-burning appliances), and
the required space between the heater and combustible material
shall be fully vented to permit the free flow of air around all
heater surfaces.
Exceptions:
1. When the masonry heater wall thickness is at least 8
inches (203 mm) thick of solid masonry and the wall
thickness of the heat exchange channels is at least 5
inches (127 mm) thick of solid masonry, combustible
materials shall not be placed within 4 inches (102
mm) of the outside surface of a masonry heater. A
clearance of at least 8 inches (203 mm) shall be provided
between the gas-tight capping slab of the heater
and a combustible ceiling.
2. Masonry heaters listed and labeled in accordance
with UL 1482 and installed in accordance with the
manufacturer’s instructions.