Chimney and Fireplace

Until recently (1970’s), chimneys and fireplaces were a normal part of home heating. In some places, they still play an important part of home heating solutions. However, most home construction today uses what are commonly referred to as “ornamental” fireplaces.

Ornamental means that they are designed for cosmetic benefit only. Most do not produce enough heat to be of an energy benefit to the home. Some models, however, have a ventilator installed, which can blow heated air into the immediate area around the fireplace. These are the exception, not the rule.

Wood-burning fireplaces are still around, but not typically part of new construction, especially here in the desert. Drought restrictions have kept wood-burning fireplaces from being used in new construction for about a decade now. For those that still exist, strict spark requirements apply to reduce the risk of fires started from sparks at the chimney source.

Chimneys come in several types and styles, including materials. These depend solely on the type of fireplace being used. For ornamental fireplaces, prefabricated chimneys are used. These are typically a metal chimney/flue inside a wood-framed and stucco-covered exterior covering.

Wood-burning fireplaces can have masonry, concrete block, and even stone fireplaces. Flues can be lined or unlined. Construction over the past 40 – 50 years includes lined chimney styles. Liners are usually made of concrete. The difference between ornamental and wood-burning include concrete flue vs metal flue. Although concrete flues can take high temperatures, many chimney fires occur when wood products are burned in metal chimney flues from ornamental fireplaces. The problem is from the source – wood products. Ornamental fires can reach temperatures of 400 – 500 degrees. Wood product fires can reach temperatures of 800 – 900 degrees, and can melt the metal chimney flues. Therefore, wood products should never be used in ornamental fireplaces for fire safety.

Chimneys should also have a spark arrestor, which helps reduce the spread of burning embers to dry brush, or the neighbors wood shake roof covered with dry pine needles…

Other chimney concerns and points of inspection are flashings, gaps, between home structure and chimney structure, Parging or cap flashings, Cracks in brick or mortar, and settlement of chimneys.

Masonry, stone or concrete block fireplaces are pretty straight-forward. Fireblock is examined for evidence of cracking inside the fire chamber. Cracks can allow heat to scorch through to surrounding materials, again contributing to chimney fires. Ash boxes should be accessible and clean. The flue should be functional, and can be fully opened or closed. Mantles and hearths should meet or exceed local construction standards, complete with a protective screen and/or tempered glass to prevent popping and burning embers from shooting out onto carpeting or other combustible materials.

Ornamental fireplaces should have tempered glass covers, and the burners should be clean and clear. The ceramic logs should be in proper designed position to direct heat flow to evenly escape the firebox. Dampers should have a block plate to prevent full closure, which could allow carbon monoxide to accumulate and dump into the living space of the home.

Since fireplaces could create a fire and health safety risk, care should always be takes to assure all items are visually and functionally tested and inspected.