19A Residential Fireplaces - Details and Construction - Technical Notes

Oct 24, 2026

Brick masonry residential fireplaces can achieve improved energy efficiency by supplying combustion and draft air from outside the structure. Thoughtful detailing and construction enhance both energy performance and structural integrity, while building codes often dictate fireplace configuration and component dimensions. Guidance covers how to design for safe containment and heat delivery to habitable spaces, isolate the fireplace from combustibles, and properly fill masonry voids to resist durability and rain penetration issues.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Introduction

Recommendations

General

Fireplace base assembly

Foundation

Exterior air supply system and ashpit

Technical Notes 19A-Residential Fireplaces, Details and Construction Rev [May 1980](Reissued August 2000) Abstract: Brick masonry residential fireplaces can be made more energy efficient by providing a source of combustion and draft air drawn from the exterior of the structure. Proper detailing and construction can also contribute to the overall performance of the fireplace regarding both energy efficiency and structural integrity. Building code requirements often control the configuration of the fireplace as well as component sizes. Key Words: Bricks, combustion chamber, energy efficiency, firebrick, fireclay, fireplaces , hearths, masonry, mortar. INTRODUCTION This Technical Notes contains recommended details and construction techniques which, when used to execute a proper design, will yield a functional, energy-efficient fireplace. These same recommendations are applicable to conventional fireplace construction when the provisions for the exterior air supply system are omitted. This is the second in a series of Technical Notes dealing with the design and construction of fireplaces and chimneys. Technical Notes 19 Revised contains a comprehensive discussion of fireplace design and materials selection. Other Technical Notes in this series address design and construction of both residential and industrial chimneys. RECOMMENDATIONS General Energy-efficient fireplaces vary only slightly from conventional fireplaces. The recommendations to construct an energy-efficient fireplace include properly sizing and locating an exterior air supply for combustion and draft air, and tight-fitting dampers. Operation of the fireplace and other devices, such as glass screens, may also substantially affect the performance of the fireplace. They are not, however, addressed in this Technical Note. Regardless of how much care is taken in the design and detailing process, workmanship remains a critical factor to the performance of fireplaces. The designer should, therefore, be familiar with the fireplace construction techniques of the locality in which the fireplace is to be built. No matter which fireplace configuration is selected by the designer, there are several common features that should be considered. Fireplaces, as discussed in this Technical Notes, are for burning wood and are not specifically designed or constructed for fuels that generate temperatures in excess of those generated by combusting wood. The primary function of the fireplace is to contain a fire safely and deliver heat to habitable spaces. The fireplace assembly must be isolated from combustible materials. General requirements incorporated into many building codes are: (1) All spaces between masonry fireplaces and wood or other combustible material should be firestopped by placing 1 in. (25 mm) of noncombustible material in such spaces. (2) In the plane parallel to the front wall of the fireplace, combustible material should not be placed within 6 in. (150 mm) of afireplace opening. (3) Combustible material within 12 in. (300 mm) of the fireplace opening should not project more than 1/8 in. (3 .2 mm) for each inch distance from the opening. A more specific discussion of these requirements or variations may be provided by local building codes. All void areas within the body of the fireplace from the foundation through the chimney should be solidly filled with masonry mortared in place. The only exceptions are the air passageway, the ashpit, the 1-in. (25 mm) airspace between the combustion chamber and the brickwork surrounding it, and the functional voids of the fireplace, such as the smoke chamber. Solidly filling the nonfunctional voids in the fireplace assembly increases its overall performance and durability as well as its structural integrity and resistance to rain penetration. All exposed mortar joints should be properly tooled. Concave jointing is preferred. For a graphic definition of fireplace components and a section through an energy-ef

FAQs

How can a brick masonry residential fireplace be made more energy efficient?

By providing an exterior source of combustion air and draft air so less heated air is drawn from inside the structure. Proper detailing and tight-fitting dampers also support efficiency.

What common safety and code-related requirements must be considered for combustible materials?

The fireplace assembly must be isolated from combustibles by firestopping gaps, keeping combustibles away from the fireplace opening, and limiting how much materials can project within specified distances.

Why should void areas within the fireplace body be solidly filled with masonry mortar?

Solidly filling nonfunctional voids improves overall performance and durability, strengthens structural integrity, and increases resistance to rain penetration, while exceptions cover specified functional passageways and chambers.

Oct 24, 2026

Upload by bocahgabuttt