Is roof diaphragm blocking required at the top plate to transfer shear from the diaphragm boundary?


See WFCM section 3.5.1.3 for depth to thickness ratios requiring blocking. Shear transfer through rafter/ceiling joist to top plate connections is assumed to happen without blocking if depth-to-thickness ratios are in accordance with WFCM 3.5.1.3. This is for diaphragm capacities in accordance with WFCM chapter 3 requirements.