Step-by-Step Guide to Measuring Roof Pitch
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Roof pitch is one of the most important measurements when planning a roofing project. It affects drainage, material selection, and installation costs. Whether you're replacing a roof or installing a new one, knowing how to calculate roof pitch ensures proper design and durability.
What Is Roof Pitch?
Roof pitch refers to the steepness or slope of a roof, expressed as a ratio of vertical rise to horizontal run. A common example is 4/12 pitch, meaning the roof rises 4 inches for every 12 inches of horizontal distance.
Why Is Roof Pitch Important?
The pitch of a roof affects:
- Water drainage – Steeper roofs shed water faster, reducing the risk of leaks.
- Material choice – Flat or low-pitch roofs require specialized materials like TPO or EPDM.
- Building codes – Some areas have pitch requirements for weather resistance.
- Installation costs – Steeper roofs are more labor-intensive and require extra safety precautions.
How to Calculate Roof Pitch
You can measure roof pitch in two ways: inside the attic or on the roof.
Method 1: Measuring from Inside the Attic
- Place a level against a roof rafter.
- Mark a 12-inch point along the level.
- Measure the vertical rise from the 12-inch mark to the rafter's surface.
- Write the pitch as "rise/run" (e.g., 5 inches of rise = 5/12 pitch).
Method 2: Measuring on the Roof
- Rest one end of a level on the roof surface.
- Measure 12 inches horizontally from the starting point.
- Measure the vertical distance from the 12-inch mark to the roof's surface.
- Record the pitch using the same rise/run format.
Common Roof Pitch Measurements
Here are typical roof pitches found in North Carolina, South Carolina, and Georgia:
- Low-Slope Roofs (1/12 to 3/12) – Common for flat and modern-style homes.
- Standard Residential Roofs (4/12 to 7/12) – Most homes have a pitch in this range.
- Steep Roofs (8/12 and higher) – Found in areas with heavy rainfall for better water runoff.
Need Help Measuring Your Roof Pitch?
If you're planning a roof replacement or new installation, getting the pitch right is essential. Contact us for a professional roof inspection and accurate measurements in North Carolina, South Carolina, and Georgia.