Masonry Magazine January 1984 Page. 30
modify the design and construction so that products readily available in the United States may be used with the brick masonry heater. The option also exists to import the accessories or to fabricate accessories similar to those used in Europe. However, these options are usually uneconomical. Additional information regarding accessories may be obtained from the cited references.
Brick
Most building codes require that solid masonry units be used for fireplace construction. Solid brick should be nominal 3 in. (75 mm) or 4 in. (100 mm) thick, conforming to ASTM C 216 or C 62, for facing brick or building brick, respectively. If a single wythe of reinforced, grouted hollow brick is used, the hollow brick should be at least 8 in. (200 mm) wide and should conform to ASTM C 652. Grade SW brick should be used because of its greater durability.
Refractory brick, conforming to ASTM C 64, medium duty, should be used for the firebox. The lining for the first baffle chamber of the contemporary-style heater and the smoke chamber of the fountain-style heater should also be constructed of refractory units because these areas are exposed to the greatest amounts of heat. The refractory units are more resistant to heat and thermal shock.
Salvaged or used brick should not be used, because they usually will not bond well with the mortar and lack the durability necessary for satisfactory performance. The use of salvaged brick is discussed in Technical Notes 15.
Flue Liners
Flue liners should conform to ASTM C 315. They should be thoroughly inspected just prior to installation for cracks or other damage that might contribute to smoke and flue gas leakage.
Mortar and Grout
It is most convenient and economical to use only one type of mortar for the entire brick masonry heater and chimney assembly. This becomes difficult when constructing a brick masonry heater because of the specific requirements of each component. The portions of the heater consisting of building, face or hollow brick should be constructed using a Type N. portland cement-lime mortar, conforming to the proportion specifications of ASTM C 270 or BIA M1-72. The same mortar should be used for the chimney brickwork except when wind loads exceed 25 psf (1.2 kPa). Where high wind loads exist, a Type S, portland cement-lime motar, conforming to the proportion specifications of ASTM C 270 or BIA M1-72, should be used. It may be desirable to use high temperature-resistant mortars, such as calcium aluminate mortars, for the interior wythes and baffles of the brick masonry heater. Such mortars will increase the durability of the heater.