Butterfly Roof

A roof with two slopes descending toward the center.

Flat Roof

A roof made of metal decking, usually with tapered-thickness insulation on top. The top planes of the roof usually slope slightly at 1/4" per 48”, toward central points where roof drains are located.

Gable Roof

A roof named for the triangular wall at its end. The roof slopes from a high point down toward the exterior walls. Sloped sides are usually at the same pitch, but can vary.

Gable Roof Parts – (1) eaves, (2) hip, (3) valley, (4) ridge.

Gambrel Roof

A symmetrical two-sided roof with two slopes on each side. The upper slope is positioned at a shallow angle and the lower slope is steep. This design provides the advantages of a sloped roof while maximizing headroom in the building's upper level.

Hip

An inclined line formed by the intersection of two adjacent sloping planes.

Hip Roof

A roof with sloped surfaces on all sides. All surfaces slope downward toward the exterior walls. Sloped surfaces can have different pitches or they can all have the same pitch.

Mansard Roof

A four-sided gambrel-style hip roof, having two slopes on each side; the lower slope has a steeper angle than the upper slope. Sloped sides can contain dormer windows to create additional habitable space.

Pitch

The slope of a roof. This is expressed as: vertical rise in inches, per foot of horizontal run.

Ridge

A horizontal line formed at the top intersection of two adjacent sloping planes.

Shed Roof

Roof with a single pitch.

Valley

An intersection of two included roof surfaces toward which rain water flows.