Standing Trusses
With the first end truss up, I like to spread the trusses if
they aren’t too big (Figure 3).
Figure
3. Unless trusses are too big to handle twice, spreading
out trusses along the top plate makes it easy to roll them up
into position later.
Spread them so that they end up leaning on top of one
another in the same order you want to follow when you stand
them up later on. Work in pairs, keeping an eye on your partner
at all times. It’s easy to knock one another off the
building if your movements aren’t coordinated. After the
trusses are all spread out, prepare and raise the other end
truss.
Inside trusses.
With
the end trusses up, raise the first inside truss and adjust it
into place. Sometimes the intersection of the bottom chord and
the tail overhang of the top chord is not easily determined
because the very tip of the bottom chord is broken or cut
short. To be absolutely sure, I run a straightedge to mark the
intersection on each truss. This way, when you are standing the
trusses, a quick glance will tell you when you’re on the
money. This prevents you from ending up with a wavy roof
line.
After the first interior truss is aligned and nailed down to
the exterior walls with two 16-penny nails at each end, finish
installing the outriggers to tie these two trusses together.
Then, before tipping up more trusses, start a piece of
temporary bracing on top of these first two trusses as close to
the peak as you can reach. Use 8-penny nails and highnail them
slightly so that they can be easily removed during the
sheathing phase. On tall trusses, you’ll need braces on
both sides to reduce the risk of cascading trusses.
From this point on, stand and space each truss using ridge
and eaves blocks at top and bottom, and the bracing layout
marks along the top chord (Figure 4).
Figure
4. A carpenter nails off the top chord brace at the
premarked layout line, automatically spacing the trusses. Note
in the background how the outriggers have been installed in
preparation for the barge rafters.