Where does the birdsmouth cut on a rafter rest?

The birdsmouth cut on a rafter is specifically designed to ensure a proper fit and load transfer to the wall framework. This cut allows the rafter to rest securely on the rafter plate, which is often referred to as the top plate.

By resting on the top plate, the birdsmouth cut provides stability and aids in the structural integrity of the roof system. It essentially helps position the rafter at the correct angle, allowing for an efficient transfer of weight from the rafter down to the wall structure below. This connection is crucial, as it prevents lateral movement and contributes to the overall strength of the roofing assembly.

In contrast, locations like the sole plate, girder, and header do not serve as appropriate resting points for the rafter. Each of these components has specific roles in the structure that do not align with the function of the birdsmouth cut. The sole plate is the bottom horizontal member of the wall, the girder is a primary support beam, and the header serves to support loads above doorways and windows. Hence, placing the rafter on any of these elements wouldn't provide the required support and alignment necessary for a properly constructed roof.