Masonry chimneys do not necessarily have to be built by a mason. Instead, the masonry chimney more describes an aesthetic design of the chimney. Commonly, a masonry chimney is made of bricks stacked together by cement. A masonry chimney has an aesthetic beauty to it that symbolizes hand-building aspects of the home. However, the masonry chimney can be a complex chimney. For example; masonry chimneys require flues, or vertical openings that control airflow to the fire. Home owners manually control their flues, requiring consistent monitoring over a fire.
In contemporary homes, a factory built chimney is most common. These chimneys are made of metal and are specially designed to trap or let out heat. Factory built chimneys are a catch-all term to all non-masonry chimneys. However, all factory chimneys are similar in that they are constructed before being installed into a home, and they are insulated on the inside of the chimney walls. The insulation can do one of two things. The metal insulation can absorb heat from the fire, and essentially, trap heat better. Or insulation allows air to circulate in the chimney, and heat to escape from the chimney easier.
Combination chimneys combine the best aspects of both factory built and masonry chimneys. Specifically, the combination chimneys looks like a masonry chimney, but it utilizes built-in metal insulation. Because there are many different types of factory built chimneys, combination chimneys mostly look like masonry chimneys with a unique inner insulation. Instead of using flues, the internal insulation of the combination chimney helps regulate temperatures.
The central issue behind all chimneys is what kind of fireplace it connects to. For example; most home builders do not have much of a choice with most factory made chimneys, since the fireplace or stove connected to the chimney is built with the chimney. However, masonry chimneys are much more flexible; if you remove a wood stove from your house, you can build in a fireplace that connects to the masonry chimney. Combination chimneys face unique issues depending on their design. In either case; although a chimney can be chosen for aesthetic or technological reasons, the best kind of chimney depends on how adaptable it is to your house.