Chapter 24 Chimneys and Fireplaces

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Explain how masonry chimneys are constructed around flue linings. Name the parts of a typical masonry fireplace. Describe procedures for the construction of the chimney, hearth, walls, and throat. Define the functions of the damper and smoke shelf. Objectives

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Calculate the flue area for a given fireplace. Describe the common types of factory-built chimneys and fireplaces. Install a factory-built chimney. List special considerations for installing factory- built fireplace units. Objectives (Cont.) Preway, Inc.

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Chimney Vertical shaft that exhausts smoke and gases Used for heating units, fireplaces, and incinerators May improve outside appearance of home

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Masonry Chimney Must have its own footing Clay flue lining should be at least 4″ thick Size depends on number, arrangement, and size of flues Must be constructed high enough to avoid downdrafts

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Flue Linings IRC, most local codes require chimneys be lined Fireclay flue linings recommended for wood- burning fireplaces Flue linings for other appliances may be made of clay or stainless steel

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Construction Each section of flue lining is set in place Lining is guide for brick work Chimneys are often corbelled to increase size of upper section Water leakage around chimney can be prevented with flashing

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Masonry Fireplaces Hearth consists of two parts: front and back Damper is located above fire to control combustion Throat, smoke shelf, and smoke chamber must be designed to ensure good operation

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Design Details Size of fireplace opening should be based on size of room Elevation and section views show details for construction of masonry fireplace

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Hearth Must be completely supported by chimney Ash dump may be provided in rear hearth Dump consists of metal frame with pivoted cover Raised hearth may be used for slab-on-grade construction

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Side and Back Walls Side and back walls of combustion chamber extend upward to level of damper Side walls are angled to reflect heat into room Slope of back wall directs smoke into throat of fireplace

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Damper and Throat Part of fireplace throat is formed by damper Damper can change direction of downdraft so smoke is not forced into room Throat size controls efficiency of fireplace

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Smoke shelf helps damper change direction of downdraft Some smoke shelves are curved to reduce turbulence Smoke chamber is space extending from top of throat up to bottom of flue Smoke chamber also lessens force of downdraft Smoke Shelf and Chamber

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Cross-sectional area of flue is based on area of fireplace opening Flue area should be at least 1/10 of total opening Larger flue may be needed to compensate for lower chimney heights Flue Size

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. During rough framing of structure –Masonry work forms main walls –Steel lintel is set and damper is installed –Smoke chamber is built –Chimney is carried upward through roof –Exterior masonry is completed Finishing stage takes place during application of interior trim Construction Sequence

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Special Designs Some fireplaces have openings on two sides When calculating flue area, sum of area of all faces must be used Special dampers with square ends and sides are available for two-way fireplaces

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Built-In Circulators Factory-built metal units used to increase heating efficiency Modified fireplaces include –Firebox and heating chamber –Throat and damper –Smoke shelf and smoke chamber Majestic Co.

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Factory-Built Chimneys Lightweight units that require no masonry work Can serve both gas fireplaces and furnaces Special flanges and fittings are used to fasten flue to building Factory-built termination tops are available

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Factory-Built Fireplaces Generally less expensive than masonry units Provide wide range of easy-to-install designs Multiple-steel-wall construction and special firebox linings may permit zero clearance

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Operation Factory-built fireplaces operate like metal circulator built into masonry fireplaces Some units can be attached to ducts that carry heated air to various locations Preway, Inc.

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Construction Fireplace frame is usually built at same time as exterior walls and partitions Facing side of frame should remain open until fireplace installed Many materials can be used to trim fireplace opening Superior Fireplace Co.

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Chimneys for Factory-Built Fireplaces Designed for specific units and usually sold along with fireplaces Openings in roof must be correct size for firestop spacers and support boxes Fireplace and chimney can be located within room or in chase Preway, Inc.

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Improve efficiency of fireplaces Can be installed on masonry structures or factory-built units Reduce amount of heated room air that escapes up chimney Control rate of burning using draft vents and dampers Glass Enclosures

Copyright Goodheart-Willcox Co., Inc. May not be posted to a publicly accessible website. Construction Careers Masons Build walls, floors, walkways, or other structures from brick, concrete block, or stone Most work for building contractors or are self- employed Learn skills from vocational programs, on-job training, or apprenticeships Digital Vision/Photodisc/Thinkstock