1. What is Rafter Pitch Length?

Rafter pitch length is the diagonal measurement of a roof's slope, calculated using the Pythagorean theorem. It represents the actual length of the rafter from the roof's peak to the edge of the building.

2. How Does the Calculator Work?

The calculator uses the Pythagorean theorem:

Where:

• \( Rise \) — Vertical height of the roof (feet)
• \( Run \) — Horizontal distance from edge to center (feet)

Explanation: This formula calculates the hypotenuse of a right triangle, where the rise and run form the two perpendicular sides.

3. Importance of Rafter Calculation

Details: Accurate rafter length calculation is essential for proper roof construction, material estimation, and structural integrity. It ensures proper fitting of roofing materials and prevents construction errors.

4. Using the Calculator

Tips: Enter the rise and run measurements in feet. Both values must be positive numbers. The calculator will compute the rafter length using the Pythagorean theorem.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between rafter length and roof pitch?
A: Roof pitch is the ratio of rise to run (e.g., 4:12), while rafter length is the actual diagonal measurement of the roof slope.

Q2: How accurate does this calculation need to be?
A: For construction purposes, rafter measurements should be precise to within 1/8 inch to ensure proper fitting and structural integrity.

Q3: Does this calculation account for rafter overhang?
A: No, this calculates the basic rafter length from peak to wall. Additional length should be added for any desired overhang beyond the building's edge.

Q4: Can I use this for different roof types?
A: This calculation works for simple gable roofs. Complex roof designs with multiple pitches may require additional calculations.

Q5: Should I add extra length for cutting and fitting?
A: Yes, it's recommended to add a small allowance (typically 1-2 inches) for cutting and fitting adjustments during construction.