A typical detail drawing of a 20foot truss rafter is shown in view
B. Use filler blocks to keep the brace members in a vertical plane,
since the rafter and bottom chord are nailed together rather than
spliced. The drawing shows placement of the rafter tie on the
opposite side from the vertical brace. Usually the splice plate for
the bottom chord (if one is needed) is placed on the side where the
rafters are to be nailed so that it can also serve as a filler block.
Use a modified truss, shown in view C, only when specified in plans
for certain construction. It should not be used in areas subject to
high wind velocities or moderate to heavy snowfall. In this type of
trussed rafter, the bottom chord is placed on the rafters above the
top plate. The construction plans specify the best type of trussed
rafter for the purpose. The drawings must show, in detail, the
construction features of the rafter selected.
g. Heavy Wood Framing. Heavy wood framing consists of framing
members (timber construction) at least 6 inches in dimension (for
example, 2 by 6 inches or 4 by 12 inches). Examples of this type
framing are heavy roof trusses, timbertrestle bridges, and wharves.
The major differences between light and heavy framing are the size of
timber used and the types of fasteners used.
h. Foundation Plan. Figure 119, page 22 shows a foundation
plan. The foundation is the starting point of the construction.
Detail drawings and specifications for a plan are usually attached on
a separate sheet.
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EN5155
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