A proper masonry chimney cap should be constructed to provide an overhang projecting beyond all sides of the chimney by a minimum of _____ inches?

A proper masonry chimney cap should indeed project beyond all sides of the chimney by a minimum of 2 inches. This overhang is crucial for several reasons.

First, the projection helps to keep rainwater and snow from entering the chimney. When water accumulates inside a chimney, it can lead to a series of problems, including damage to the chimney structure and deterioration of the flue liner. Adequate overhang prevents moisture from seeping into the masonry, thus extending the lifespan of the chimney.

Second, the overhang aids in directing water away from the sides of the chimney, reducing the likelihood of erosion or washing away of the mortar joints. This is essential for maintaining the structural integrity of the chimney.

Lastly, having a minimum of 2 inches of overhang helps ensure that combustible materials, such as roofing or siding, remain protected from potential heat or embers escaping from the chimney, thereby contributing to fire safety.

The specified measurement is derived from industry standards that emphasize both functionality and safety in chimney design.