What is the standard roof pitch?
Short answer. There is no one standard roof pitch required for houses, but builders treat roughly 4/12 to 9/12 as conventional, and 6/12 is a common default on house plans. What is standardized are the minimums: building codes set the lowest pitch each roofing material can be installed on, such as 2/12 for asphalt shingles.
Three meanings of standard
- Builder standard: plan sets and truss suppliers often default to 6/12 or 8/12 main roofs because they look right, drain well and keep framing economical.
- Roofer standard: 4/12 to about 7/12 or 8/12 is conventional, walkable work; steeper is billed as steep.
- Code standard: the International Residential Code, which Georgia adopts with state amendments, sets material minimums, not a preferred pitch.
Code minimums by material
- Asphalt shingles: 2/12, with two layers of underlayment from 2/12 up to 4/12.
- Lapped metal panels without lap sealant: 3/12.
- Standing seam metal: as low as a quarter inch per foot.
- Clay and concrete tile: 2.5/12 with double underlayment.
- Slate: 4/12.
Standard pitches for porches and sheds
Porch roofs, sunrooms and small additions often use 3/12 or 4/12 so they fit under second-floor windows. If that puts a shingled porch below 4/12, it needs the low-slope underlayment detail; anything below 2/12 needs a membrane or standing seam metal instead. These low tie-ins are among the most common leak spots on Georgia homes, usually where the porch meets the wall.
Why it matters at replacement time
A new roof keeps the pitch you already have, but that pitch decides the underlayment, the labor and part of the price. A careful estimate lists each pitch section separately. See our measuring guide and our underlayment comparison for what changes on low slopes.