Are all masonry chimneys required to have a liner under code?

The correct answer indicates that all masonry chimneys are indeed required to have a liner under code. This requirement is established to ensure safety and efficiency in venting combustion products from fireplaces, woodstoves, and gas appliances. A liner serves several important functions: it helps protect the masonry structure from heat and corrosion, enhances the draft performance, and minimizes the risk of chimney fires by containing soot and creosote within the liner.

This code requirement aims to improve the overall performance of the chimney and safeguard the building's integrity and the safety of its occupants.

In this context, while there may be scenarios where specific types of appliances or chimney heights can influence certain code applications, the fundamental requirement for a liner across all masonry chimneys underscores the emphasis on safety and efficiency in ventilation.