Common Rafter Length (CRL) Calculator





Formula

The formula to calculate the Common Rafter Length (CRL) is:

\[ CRL = \sqrt{(RS^2) + (RL^2)} \]

Where:

What is Common Rafter Length?

A Common Rafter Length is a measurement used in roofing construction that refers to the length of the rafter, which is the beam running from the top of the roof to the bottom. This length is determined by the width of the building, the pitch (or slope) of the roof, and the thickness of the ridge. It is a crucial measurement for ensuring the structural integrity and proper construction of a roof.

Example Calculation

Let's assume the following values:

Step 1: Calculate the Common Rafter Length (CRL):

\[ CRL = \sqrt{(15^2) + (10^2)} = \sqrt{225 + 100} = \sqrt{325} \approx 18.03 \text{ feet} \]

Therefore, the common rafter length is approximately 18.03 feet.