Roof pitch reference
14/12 roof pitch
A 14/12 roof rises 14 inches per 12 inches of run: 49.4°, a 116.7% grade, slope factor 1.5366. Each foot of run is 18.44 inches along the slope.
√(1 + (14 ÷ 12)²) = 1.5366 · between 13/12 (+47.4%) and 15/12 (+60.1%).
Roof area at 14/12
| Footprint | Roof at 14/12 | Squares |
|---|---|---|
| 1,200 sq ft | 1,844 sq ft | 18.4 |
| 1,600 sq ft | 2,459 sq ft | 24.6 |
| 2,000 sq ft | 3,073 sq ft | 30.7 |
| 2,600 sq ft | 3,995 sq ft | 40 |
Rafter length at 14/12
| Run (half span) | Rafter, no overhang |
|---|---|
| 10 ft | 15 ft 4.5 in (15.37 ft) |
| 12 ft | 18 ft 5.25 in (18.44 ft) |
| 14 ft | 21 ft 6.25 in (21.51 ft) |
| 16 ft | 24 ft 7 in (24.59 ft) |
Ice barrier on a 14/12 roof in Ohio and Michigan
Freeze-thaw winters in both states make eave protection one of the most important details on a 14/12 roof. Where the locally adopted code requires it, the model IRC (R905.1.2) extends ice barrier from the eave to at least 24 inches inside the exterior wall. On a 49.4° slope that distance grows by 53.7% when measured up the roof:
| Overhang | Horizontal | Up the 14/12 slope | 36-in courses |
|---|---|---|---|
| 12 in | 36 in | 55.3 in | 2 |
| 18 in | 42 in | 64.5 in | 2 |
| 24 in | 48 in | 73.8 in | 3 |
Courses assume a 3-inch lap (33 inches of coverage per 36-inch roll). Wall thickness adds a few inches. Check the product and your building department.
Shingles at 14/12
At 14/12 (49.4°, 116.7% grade) asphalt shingles install with standard underlayment under the IRC, plus ice barrier where the local code requires it.
Working on a 14/12 roof
A 49.4° slope behaves almost like a wall. A 14/12 roof needs full staging and fall protection, and shingle makers publish separate steep-slope application steps, such as extra nails and hand-sealing, for pitches like 14/12. OSHA treats anything steeper than 4/12 as a steep roof, so 14/12 falls under steep-roof fall protection rules.
Frequently asked questions
What angle is a 14/12 roof?
A 14/12 roof is about 49.4° from horizontal, a 116.7% grade. Over a 10-foot run it rises 11.67 feet.
How much bigger is a 14/12 roof than the footprint?
The slope factor is 1.5366, so the roof is 53.7% larger than the flat area under it. A 1,600 sq ft footprint has about 2,459 sq ft of roof (24.6 squares).
Can you put asphalt shingles on a 14/12 roof?
At 14/12 (49.4°, 116.7% grade) asphalt shingles install with standard underlayment under the IRC, plus ice barrier where the local code requires it.
How much ice barrier does a 14/12 roof need at the eaves?
With a 12-inch overhang, reaching 24 inches inside the wall takes about 55.3 inches measured up a 14/12 slope, which is 2 courses of 36-inch membrane with a 3-inch lap. Your local code decides whether ice barrier is required.