Roof pitch is the measure of a roof’s slope or angle of incline. Is there a difference between pitch and slope? Yes...and no. To understand how to properly use these terms, a brief lesson in roof geometry helps.

Roof pitch is expressed as a fraction, such as 1/4, each number representing the coordinates of an angle. That angle is based on a roof’s rise (height) and span (width). Pitch is the rise over the span.

Say your house is 38 feet wide and the gable roof has a 1-foot overhang on each side; that makes the roof’s span 40 feet. From the eaves to the peak, it’s 10 feet high—that’s the rise. Figure 10/40 and reduce that to 1/4. It has a 1/4 pitch.

Okay, then, what’s its slope? A roof’s slope is the number of inches it rises for every 12 inches of horizontal “run” A roof with a “4-in-12 slope” rises 4 inches for every 12 inches of horizontal run. The same roof has a 4/12—or 1/3—pitch. Pitch and slope are simply two different ways of expressing the same measurement.

The word “pitch” was first used in the early 17th century to denote “the highest point.” This referred to everything from musical sound to the height that a falcon reaches before swooping down to attack its prey.

Part of a roof’s frame, a ridgeboard runs horizontally along the peak of a sloped roof. Essentially the spine of a conventional stick-framed roof, the ridgeboard is sandwiched between the meeting ends of the roof rafters.

Spelled “hryge” in Old English, the word “ridge” was first used in reference to house roofs in the 16th century. In the 17th and 18th centuries, “ridge-piece” and “ridge-pole” were used respectively to designate a horizontal timber or a pole at the ridge of a roof. What was once a pole or timber is now a milled board— typically a 1 by 6 or larger for houses—hence, today’s modification of the term to “ridgeboard.”

Although the gambrel roof is popular for certain house styles, most notably Dutch Colonials native to the Hudson River Valley, perhaps it is most familiar capping the barns that dot rural countrysides.

A gambrel roof has a straight ridge like that on a gable roof, but midway down the slope, the planes break downward at a steeper pitch. A gambrel roof is so named because its curved, hip-like shape resembles the contour of a horse’s hind leg, called a hock or gambrel in 17th-century England.

This type of roof utilizes two shorter rafters in place of each single rafter that spans a typical gable roof. This is an advantage where quality rafter material is scarce, but gambrel roofs are slightly more complicated to frame. Their greatest advantage is that they allow maximum living or storage space in the attic or upper-floor level.

A soffit is the horizontal underside of a roof overhang, an archway, a staircase, a ceiling, or a similar architectural component.

From the Italian “soffitta” for under and “figgere,” to fix, the word “soffit” dates back to the days of early Palladian architecture.

Typical soffits on today’s houses include the flat area under the eaves where vents provide attic ventilation, the lower perimeter of a drop ceiling, and the ceiling that is mounted to the underside of a staircase.