Are Birdsmouth Cuts Really Necessary?

One of the hallmarks of a good framing carpenter is the ability to accurately lay out and cut rafters. Learning to make the “birdsmouth” cut – where the rafter bears on the top plate – is a kind of milestone in the apprenticeship of a young carpenter, but in this classic JLC Forum thread, the argument is made that this step is not only unnecessary but potentially weakens the rafter. Like most JLC Forum threads, the ensuing discussion amongst both newbies and veteran carpenters remains civil while offering different points of view about the pros and cons of the birdsmouth cut.