Guide
Roof Types Explained
Roof "type" means two different things: the shape of the structure and the material covering it. This guide covers both, with what each costs and how long it lasts.
The most common residential roof shapes are gable, hip, flat, shed, gambrel and mansard. The most common materials are asphalt shingle, metal, tile, slate, wood shake and membrane. Gable roofs with asphalt shingles are the default across most of the United States because they are the cheapest combination that performs well.
Roof shapes
The shape determines how water leaves the roof, how the building handles wind, and how much usable space sits underneath. It is fixed at construction and expensive to change later.
Shown end-on, because the profile is what separates these shapes. A gambrel is a gable with a knuckle in each slope; a mansard is that same profile taken around all four sides; a shed is one half of a gable.
- Gable
- Two slopes meeting at a ridge, with vertical triangular ends. Cheapest to build, sheds water and snow well, easy to ventilate. The vertical gable end catches wind, which makes it the weakest common shape in hurricane country. Its rafters are the simplest to size, with the rafter calculator.
- Hip
- All four sides slope down to the walls. Much better in high wind because there is no flat end to push against, and often earns an insurance discount. Costs 10 to 15% more than a gable and gives less attic space. The hip roof calculator works out its area and hip rafter lengths.
- Flat
- Not truly flat, since code requires at least 1/4 inch per foot of fall. Standard on commercial buildings and modern homes. Cheapest to build per square foot, but drainage is critical and lifespan is shorter. Membrane prices are on the flat roof cost calculator.
- Shed
- A single slope, like half a gable. Common on additions, porches and modern architecture. Simple, cheap, and easy to build, but it dumps all its water on one side, so the gutter on the low edge carries the whole roof.
- Gambrel
- Two pitches per side, steep below and shallow above. The barn profile. Maximizes usable loft space under the roof, at the cost of a horizontal break line that needs careful flashing. The gambrel roof calculator handles its two pitches.
- Mansard
- A gambrel on all four sides. French in origin, and the shape that gives a full extra usable floor. The most expensive common shape to build and to re-roof.
Other shapes, and what they do to the price
Most houses are one of the six shapes above or a combination of them. These five turn up often enough to be worth naming, and each changes the cost of a roof in a way the pitch and the area alone do not show.
- Saltbox
- A gable with one long, low slope at the back and a short, steeper one at the front. Colonial New England in origin. Re-roofing costs about what a gable of the same area does, but check the pitch of the long slope: if it falls below 4/12, asphalt shingles need doubled underlayment there.
- Dutch gable
- A hip roof with a small gable, sometimes called a gablet, at the top of each end. It keeps most of the hip roof's wind resistance and adds a vent opening at the peak. Every gablet adds cuts and flashing, so it re-roofs for more than a plain hip.
- Cross-gable and cross-hip
- Two or more gable or hip sections meeting at right angles, the usual roof on an L- or T-shaped house. Every inside corner is a valley, and valleys are where most leaks start and where shingle waste climbs, so the more intersections a roof has, the more it costs per square to replace.
- Butterfly
- Two slopes falling toward a central valley, an upside-down gable. Common on architect-designed modern houses. All the water ends up in that one valley, so it needs a membrane system and drainage that never clogs, which makes it among the costliest shapes to keep watertight.
- A-frame
- A steep gable whose slopes run nearly to the ground, so the roof is also most of the walls. The roof area is large for the floor area beneath it, and the pitch is far past walkable, so every square needs staging and fall protection. Expect a high labor cost per square.
Roofing materials compared
Material choice drives cost far more than shape does, and within asphalt there are three grades to choose between. The table below is installed cost per square foot of roof for a full replacement of a 1,700 sq ft house at a 6/12 pitch, tear-off and permit included, computed from the same material and labor dataset as the calculators.
| Material | Installed / sq ft of roof | Lifespan | Best for |
|---|---|---|---|
| Asphalt shingles, 3-tab to architectural | $4.47 – $6.73 | 15 – 30 yr | The default choice for most homes; 3-tab sits at the low end |
| Metal, exposed fastener | $6.15 – $8.80 | 25 – 40 yr | Outbuildings, barns, budget metal |
| Metal, standing seam | $12.00 – $18.00 (typical) | 40 – 70 yr | Long-term ownership, wildfire zones |
| Clay or concrete tile | $8.00 – $13.09 | 50 – 100 yr | Hot and dry climates, Spanish styles |
| Natural slate | $18.94 – $34.17 | 75 – 150 yr | Historic homes, permanent roofs |
| Cedar shake | $11.31 – $18.14 | 25 – 40 yr | Traditional aesthetics, mild climates |
| TPO membrane | $4.94 – $8.60 | 20 – 30 yr | Flat and low-slope roofs |
Standing seam is marked typical: it is a published range for a system our dataset does not price. Every other row is computed. Price a specific roof with the roof replacement calculator.
How to choose
Start with slope. Below 2/12 you must use a membrane; asphalt shingles are not permitted and will leak. Between 2/12 and 4/12, shingles work but need doubled underlayment. Above 4/12 everything is on the table.
Then weigh how long you will own the house. Metal and tile cost two to three times asphalt but last three times as long, so on cost per year of service they are competitive, but only if you stay long enough to avoid paying for a second asphalt roof.
Finally check the structure. Tile and slate weigh three to ten times what asphalt does. Putting either on a house framed for shingles requires structural reinforcement, and that engineering assessment has to happen before you commit to the material.