The line length
of common and hip rafters can be
calculated by using the dimensions shown in figure 2 and the
Frederickson Metric Framing Square rafter table. Line lengths lie
between two working points. The line length of the common rafter is
calculated first.
Run = span of 6400 mm divided by 2 = 3200 mm. The common rafter unit of
run length is 250 mm. The number of units of run
for the common rafter is = 3200 mm divided by 250 mm = 12.8. The unit
of
length of the common rafter with a 150/250 slope is 291.5mm. The line
length of
the common rafter in figure 2 is 291.5 mm times 12.8 = 3731.2
mm.
