Masonry Magazine February 1996 Page. 56
Continued from Page 19
Liners were often used in the past, most masonry heater builders do not recommend them because of problems associated with their use. The size and configuration of the heat exchange channels depends on the type and size of the masonry heater.
Metal Parts
Metal parts in a masonry heater should be avoided whenever possible. Necessary elements such as the firebox door(s), damper, lintels, ash and clean-out doors, must be placed to allow for thermal expansion. Parts, like the firebox door(s), which require a tight seal are usually placed with a fireproof gasket surrounding the metal frame to accommodate the thermal movement. Metal ties between wythes of the heater, recommended in some early designs, are no longer recommended due to the cracks associated with their use.
The Chimney
Many masonry heater professionals recommend masonry chimneys because of their heat-storing properties, but metal flues can be used. The minimum flue size typically used to vent any masonry heater is an 8 in. by 8 in. square or 8 in. diameter round clay flue. The chimney should be constructed so that it does not bear on the inner walls of the masonry heater. Often, the chimney is built separately from the heater, only connected at the chimney base, to minimize cracking due to the temperature differential between the high-temperature masonry heater and cool chimney.
Finishing the Heater
The outward appearance of a masonry heater is limited only by the designer's imagination. Brick, field stone, soapstone, stucco and ceramic tiles are all acceptable finishing materials. Masonry heaters may have a rustic appearance or a sleek, contemporary one. Often, masonry heaters include niches for firewood, decorative alcoves, mantels, warming benches and sometimes bake ovens. A brochure illustrating a few of the possibilities with masonry heaters can be obtained by contacting the Masonry Heater Association of North America (MHA).
MHA is a trade association representing masonry heater builders and manufacturers. Membership includes a quarterly newsletter, membership meetings and seminars. For further information contact MHA at 11490 Commerce Park Drive, Suite 300. Reston, VA 22901, (703) 620-3171.
Saltzman
"But I didn't say you were getting wrinkles. I only asked if you wanted some grouting for your cosmetics collection."
References: (1) ASTM Standard E 1602. "Guide for the Construction of Solid Fuel Burning Masonry Heaters," ASTM, Philadelphia, PA, 1994; (2) Barden, A. and Hyytiainen, H., Finnish Fireplaces-Heart of the Home, The Finnish Building Centre Ltd., Helsinki, Finland, 1993; (3) Stroud, T. R. and Crooks, R. B., "Masonry Heaters: Clean Wood Burning Technology Outside EPA's Certification Program," Proceedings of the meetings of the Pacific Northwest International Sector of the Air & Waste Management Association, Victoria, British Columbia, Canada, 1993.
Bon Tool Co.
America's Finest Quality
Bon Tool Co.
Supplying the tools that build America
4430 Gibsonia Rd., Gibsonia, PA 15044 412-443-7080
56 MASONRY-JANUARY/FEBRUARY, 1996