gable roof
A single-ridge roof that terminates at gable ends.
Gable roof: two slopes meeting at a peak
A gable roof is a pitched roof constructed from two sloped planes that meet at a central ridge, creating a triangular wall section, called a gable, at each end of the building. This is the most common roof form in residential construction because it sheds water and snow reliably and requires minimal framing complexity compared to other pitched roof types.
The two roof planes, called rafters or trusses, typically slope at angles between 4:12 and 12:12 pitch (4 to 12 inches of vertical rise per 12 inches of horizontal run). Steeper pitches increase attic volume and improve drainage in wet climates; shallower pitches save material but must be paired with adequate underlayment and guttering in areas with heavy rainfall or snow load. The ridge beam or board at the peak carries loads from both slopes and must be sized and braced according to span and load calculations.
The triangular gable end walls are typically left open as a framing void or infilled with siding, brick, or other cladding. This geometry creates useful attic space, though ventilation must be managed carefully. Moisture and heat accumulation in attic cavities can shorten roof life and damage structural members, so gable roofs typically include soffit and ridge vents or active ventilation.
Gable roofs fail most often where water penetrates at the junction of roof and gable walls, where flashing is undersized or corroded. Wind uplift is another common failure mode, especially on edges and at gable ends where pressure concentrates. Inadequate collar ties or collar bracing between opposite roof slopes allows the weight and thrust of the rafters to push the gable walls outward, cracking masonry or splitting wood framing.
The term gable appears in Old Norse and Old High German, referring to the triangular portion of a wall above the eaves. The roof shape earned its name from this end wall, not the reverse. Variants include cross gables, dutch gables (with a small roof section atop the gable triangle), and gambrel roofs, which are double-pitched and enclose more volume but require more complex framing.