1/12 roof pitch

4.76° angle

A 1/12 roof rises 1 in for every 12 in of run: a 8.3% slope with a 1.003 area multiplier.

Pitch1 in 12 (1:12)
Angle4.76°
Slope8.3%
Roof area multiplier1.0035
Rafter length per foot of run12.04 in
TypeA flat or low-slope roof

Roofing for a 1/12 pitch

Too flat for shingles or standing water will back up under them. Use a membrane roof (EPDM, TPO or modified bitumen). Walkable for most people with care and soft-soled shoes.

Rafter length at 1/12

Run (half the span)RiseRafter length (before overhang)
10 ft0.83 ft10.03 ft
12 ft1 ft12.04 ft
14 ft1.17 ft14.05 ft
16 ft1.33 ft16.06 ft

Change the numbers

Roof pitch

1/12

4.76° angle, 8.3% slope.

Pitch1 in 12
Angle4.76°
Slope8.3%
Roof area multiplier1.0035
Rafter length per foot of run12.04 in

Other roof pitches

Questions

What angle is a 1/12 roof pitch?
4.76 degrees.
What is a 1/12 roof pitch as a percentage?
8.3%: the roof rises 1 inches for every 12 inches of run.
What is the roof multiplier for a 1/12 pitch?
1.003. Multiply the roof’s flat footprint by 1.003 to get its actual surface area.
Is a 1/12 roof walkable?
Walkable for most people with care and soft-soled shoes.

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