Hip roof

A hip roof is a pitched roof form where all four sides slope down from a central ridge or peak, meeting external walls at the eaves. Hip rafters run diagonally from each external corner of the building up to the ridge (or to a hip point in pyramid-shaped variations). Compared to gable roofs (two slopes only, with vertical end walls), hip roofs perform better in wind and are more visually balanced, but cost more to frame and produce a more complex valley-and-flashing geometry.

Variants:

• Standard hip: a long ridge with hip rafters at each end.
• Pyramid hip (rare): no ridge; four hip rafters meeting at a central point. Used on square-plan rooms.
• Hip-and-valley: hip rafters intersecting with valleys where a hip plane meets a perpendicular gable or wing.
• Dutch hip: combines a hip with a small gable at the top of each hip end. Provides natural ventilation and a different aesthetic.

Hip roof vs gable roof:

Property	Hip roof	Gable roof
Wall types	All four walls bear the roof	Two side walls bear; gable ends are non-load-bearing
Wind performance	Better; uplift is reduced because all faces slope down	Worse; wind hits the gable end face directly
Visual	Symmetric; appears smaller, more compact	Linear; emphasises length
Framing complexity	Higher; hip rafters, jack rafters, valley rafters	Lower; common rafters, ridge, collar ties
Cost	10-25% more than gable for the same footprint	Baseline
Roof space ventilation	Lower (no gable vents available)	Higher (gable vents possible)

Framing components in a hip roof:

• Ridge: structural member at the apex (ridge beam or ridge board per design).
• Hip rafter: diagonal rafter from each external corner to the ridge. Carries hip-plane and jack-rafter loads.
• Common rafter: runs perpendicular to the ridge, from ridge to wall plate, at standard rafter spacing.
• Jack rafter: runs from the hip rafter to the wall plate, shorter than common rafters as it approaches the corner.
• Valley rafter: where two roof planes intersect inward (less common on simple hip, more common on hip-and-valley).
• Valley jacks: short rafters from the valley to the ridge or to the hip rafter.

Span tables and AS 1684. AS 1684.2 publishes span tables for hip and valley rafters in MGP and F-grade pine, with adjustments for the geometry. Hip rafters typically need a larger section than common rafters because they carry more area and span further (the diagonal length is longer than the perpendicular).

Common framing complexities:

• Hip rafter sizing: the diagonal length and load tributary area make sizing more involved than gable.
• Top-plate join at corners: the top plate must be continuous around the corner; corner-bracing detail matters.
• Tie-down at hip ends: the hip end of the wall plate sees the most uplift in wind. Type-and-spacing of tie-downs per AS 1684 wind class.
• Hip rafter bevel cuts: every cut on a hip rafter is a compound bevel. Carpenter skill matters.

Roof line geometry:

• Pitch: hip rafters are at a shallower angle than common rafters (because their horizontal projection is longer for the same height to ridge).
• Fascia line: must follow the wall line cleanly at the eaves; the corner of the building is a key sight line.

For builders:

1. Spec the framing class (truss vs traditional) at design. Truss-roof hip is much simpler than traditional cut-on-site hip.
2. Get the hip rafter sizes from the engineer or span tables; don’t size by eye.
3. Watch the corner detail at PCI: a sloppy corner produces a wavy roof line that’s visible from the kerb.

Also known as: hipped roof, all-hip roof, pyramid roof (for the rare four-sided no-ridge variation).

Category: Practical / framing / roofs.

Related

• Roof framing trusses
• AS 1684
• Ridge board
• Ridge beam

See also

• Valley gutter
• Fascia

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Last updated: 2026-05-14. Verified: 2026-05-14.