Roof shape
What is a gable roof?
The roof a child draws: two slopes, one ridge, a triangle at each end. Simple to build, easy to vent, and the shape that wind engineers worry about most.
Updated September 12, 2026 · Every figure links to its source · Sources
DefinitionShapeAlso called: pitched roof, peaked roof
Gable roof — a roof formed by two sloping planes that meet at a central ridge and are closed at each end by a vertical triangular wall — the gable; the NRCA glossary defines the gable as that end wall, and the roof takes its name from it.
What it is
Every gable roof has the same parts: a ridge along the top, two rakes running down the gable ends, two eaves along the low sides, and two triangular gable walls, usually of the same material as the walls below, often with a vent near the peak. Variations are named by what is added — a cross-gable where two gable roofs meet at right angles, forming valleys; a front gable where the triangle faces the street; a Dutch gable where a small gable sits on top of a hip.
Its virtues are the reasons it is everywhere: simple framing with common rafters or plain trusses, steep enough slopes to shed rain and snow, a roomy attic, and straightforward ventilation from soffit to ridge under IRC Section R806.
Why it matters
The gable wall is a sail. In high wind the pressure on the windward gable and the suction on the leeward one push the whole end of the roof sideways, and an unbraced gable end can rack and collapse inward while the rest of the house stands. The IBHS wind research has documented this in full-scale tests, which is why gable-end bracing is a requirement of the FORTIFIED Silver level and why, other things equal, hip roofs come through hurricanes better than gable roofs. The IRC, Section R802 sets the framing rules — rafter sizes, rafter ties and collar ties — that keep the two slopes from spreading and the gable ends tied to the structure.
In hail and ordinary weather a gable roof has no special weakness, and its two large plain slopes are the easiest kind to inspect and re-cover. The rakes are the edge to watch: wind gets under a rake as readily as under an eave, and the drip edge rule in Section R905.2.8.5 applies to both.
What it costs and who does it
A gable roof is the cheapest shape to re-cover: two rectangles, few cuts, little waste, and only the ridge to cap. The estimate is by the square, with pitch and storeys as the main labour variables; cross-gables add valleys, which add labour and flashing. Any roofing contractor does the work, and a framing contractor or engineer handles gable-end bracing if a wind retrofit is wanted. The directory's guide to a new roof installation describes the sequence, and the directory's roofing squares calculator turns the roof's footprint and pitch into the area a quote is based on.
Frequently asked questions
Short answers; the sections above carry the detail and the sources.
What is the difference between a gable roof and a hip roof?
Why are gable roofs vulnerable in hurricanes?
What is a cross-gable roof?
Next step
Find a roofer who does this
A gable roof is the simplest re-roof there is, which makes the contractor's care with the rakes, ridge and valleys the whole difference. The directory lists roofing contractors by state and city.
Sources
- Roofing glossary — National Roofing Contractors Association (NRCA)
- 2021 International Residential Code, Chapter 8: Roof-Ceiling Construction — International Code Council (ICC)
- Wind research — Insurance Institute for Business & Home Safety (IBHS)
- 2021 International Residential Code, Chapter 9: Roof Assemblies — International Code Council (ICC)