As a builder turned lumber industry representative, I've
seen a lot of roof framing — some good, some not so
good. It seems that houses have become larger and their roof
systems more complicated. In light of this, it's worth revisiting
the most common framing errors I see on both conventional
and truss-framed roofs.
A common error with low-slope rafters is excessive cutting
of the rafter seat. This leaves the rafter bearing not on the
heel of the seat cut, as it should, but on the toe (see Figure 1).
The seat cut may run straight from toe to heel, or there may
be a deep birdsmouth at the