2. All of the rafter length calculations are line lengths since the
thickness of the material is not taken into account. After the line
length of the common rafter is determined and marked on the
rafter stock, then a 2nd ridge plumb cut line is drawn at exactly ½
the thickness away from the 1st line, measured perpendicularly.
CARPENTRY, 2ND Canadian Ed., Vogt F. & Nauth M., Nelson Education, 2013
5. CARPENTRY, 2ND Canadian Ed., Vogt F. & Nauth M., Nelson Education, 2013
The Framing Square, with the stair
gauges set at 6” & 12”, is used to mark
the ridge plumb cut line at the top
end of the rafter. The distance
between the gauges is exactly 13.42”.
[6:12 slope].
The Speed Square pivots at the top to
make the cut lines. Here it is set so
that the number ‘8’ below the slot is
on the top edge and the angle of cut
is 34 . [8:12 slope].
