Roof shapes
| Shape | What it looks like | What it means for the roof |
|---|---|---|
| Gable | Two slopes meeting at a ridge, with a triangle wall at each end | The simplest to frame and roof; the gable ends take the wind |
| Hip | Slopes on all four sides meeting at a ridge or a point | No gable walls; hips add cutting, waste and ridge cap |
| Dutch gable | A hip roof with a small gable at the top of each end | Hip roof details plus small gables to flash |
| Gambrel | Two slopes on each side, the lower one steep (the barn roof) | Room under the roof; the steep lower slope is slow to work on |
| Mansard | Four sides, each with a steep lower slope and a shallow upper one | A full story under the roof; the low upper part needs a low-slope covering |
| Shed | One slope, high on one wall and low on the other | Simple; often a membrane if the pitch is low |
| Flat (low slope) | Nearly level, with just enough fall to drain | Needs a membrane, not shingles |
Many houses mix them: a main gable with a hip porch, dormers, valleys where two roofs meet. Every valley, hip and dormer adds flashing, cutting and waste, which is why a cut-up roof costs more than a plain one of the same size. The guide to the parts of a roof names each line and layer.
Roofing materials
| Material | Lowest pitch the code allows |
|---|---|
| Asphalt shingles (3-tab and architectural) | 2/12, with two layers of underlayment up to 4/12 (R905.2.2) |
| Metal roof shingles | 3/12 (R905.4.2) |
| Clay and concrete tile | 2 1/2/12 (R905.3.2) |
| Slate | 4/12 (R905.6.2) |
| Wood shingles | 3/12 (R905.7.2) |
| Wood shakes | 3/12 (R905.8.2) |
| Modified bitumen | 1/4/12 (R905.11) |
| Single-ply membranes (EPDM, TPO, PVC) | 1/4/12 (R905.12, R905.13) |
Sections are from the 2021 International Residential Code, which most states adopt in some edition; local amendments can differ.
Asphalt shingles
The most common roof on American houses. 3-tab shingles are a single flat layer cut into three tabs; architectural (laminated) shingles have two layers bonded together for a thicker, shadowed look. Most of both come three bundles to a square of 100 square feet.
Metal
Standing-seam panels and metal shingles. Panels run from eave to ridge and can go on lower slopes than shingles; metal shingles mimic slate or shakes and need at least 3/12. The metal roof cost guide prices steel panels on typical houses.
Tile and slate
Heavy materials: the roof framing has to carry them, and they need a steeper pitch than shingles. Tile is common in the South and West; slate in older homes in the Northeast.
Wood shingles and shakes
Shingles are sawn smooth; shakes are split, thicker and rougher. Both need at least 3/12.
Low-slope membranes
Flat and nearly flat roofs are covered with a continuous membrane: modified bitumen in rolls, or single-ply sheets of EPDM (rubber), TPO or PVC, seamed together. The guide to EPDM roofing covers the rubber roof and its cost.
Common questions
What are the most common roof types?
The common shapes are gable, hip, Dutch gable, gambrel, mansard, shed and flat, often mixed on one house. The common coverings are asphalt shingles, metal, tile, slate and wood on sloped roofs, and membranes on flat and low-slope roofs. The gable roof guide and the hip roof guide measure each.
Which roof shape is best for wind?
Hip roofs have no tall gable ends for the wind to push on. Fastening and the roof’s connections to the walls matter as much as the shape.
Is a hip roof more expensive than a gable roof?
Usually, for the same house. A hip roof has more edges to cut, more ridge and hip cap, and more waste. The roofing calculator works out both shapes.
What’s the difference between pitch and slope?
Pitch is the rise in inches over 12 inches of run (6/12); slope is often given as a percent or an angle (50%, 26.6°). The guide to finding a roof’s pitch converts between them.