[Ed Ridgeway]

This fireplace/chimney exceeds the maximum for corbelling in my opinion. Or is there another way to build this brick and tile lined flue with these turns and not label it corbelling? Is there a condition that allows the builder to deviate from the code?

Thanks,

Ed

[Dale W. Feb]

Ed,
The current IRC states no more than one-half the unit height or one-third the unit depth (whichever is less). However, most AHJ will allow a slight variance if the proper credentialed engineer does the math. The weight of the material above, the strength of the material and the application of material are all key concerns. We as inspectors should hold our opinion based on the minimum code requirements and not recommend anything less. We do not have the authority but we area allowed our opinion. The engineers area not always right and it is our job to just "raise the question".