GROWSPAN
™
ROUND PREMIUM HIGH TUNNELS
11
Revision date: 11.22.21
10. Move to
the last two rafter joints
and install the first
section (#131S075) of those purlins. Verify the rafter
spacing is 4' on-center, and tighten the end clamps
and cross connectors.
Do not install the top, center
purlin until the entire frame is assembled.
FRAME ASSEMBLY (continued)
NOTE:
Each purlin assembly consists of 1.315'' x 75''
(#131S075) swaged pipes (quantity is determined by
shelter length) and one (1) 1.315'' x 73.5'' (#131P0735)
plain pipe to end each purlin run.
Consult the Side Profile diagram in the Quick Start
section for your building for additional details.
11. Continue adding rafters and purlin pipe until the frame
is assembled.
Secure each purlin splice using a Tek
screw. See diagram that follows.
12. Finish each purlin run using the plain, pipe
(#131P0735), and use the final end rafter to complete
the assembly. If the last end rafter is plumb and the
purlin run extends beyond the end of the rafter, cut the
last section of purlin pipe to the required length.
Install next two purlins at the
rafter joints in the locations circled
in this diagram. Dashed lines
represent the next purlin pipes.
NOTE:
Typically purlin pipes
do not
require cutting.
Verify that you have the correct plain pipes before you
decide to cut any pipe to complete the purlin runs.
To prevent cover damage, do not allow the plain end of
any purlin to extend beyond the end of the end rafter.
Align with the center of the end rafter for best results.
If the purlin is too short to fit into the rafter end clamps
without pulling the end rafter out of plumb, first verify
you have the correct pipe. If so, loosen a purlin splice
and slide the pipes apart. At least half of the tapered
end must remain inside the adjacent pipe. Drive the Tek
screw back into the pipe to secure the purlin joint.
13. Once all rafters are set and the four (4) lower purlins
are in place and secured, return to each pipe splice
of each purlin run and verify that a Tek screw secures
each joint. Install a Tek screw (if needed).
14. Continue by installing the top, center purlin.
Position the bolt side of the end clamps toward the
inside of the shelter—the same side as the purlin.
INSTALL TOP, CENTER PURLIN
Complete the following steps:
1. Move to one end of the assembled frame, find the
center of the end rafter, and mark the top, center
location on the outside face of the end rafter.
2. Move to the other end of the frame and repeat the step
to find the top, center of that end rafter.
3. To keep the top purlin parallel with the lower purlins,
take a chalk line, stretch it between the two marks, and
snap it to mark the position of the top purlin.
NOTE:
For buildings longer than a typical chalk line,
find the center of an interior rafter and snap the chalk
line using that mark and the mark on the end rafter.
Repeat as needed to mark all rafters.
Mark the center of the end
rafter at both ends to position
the top, center purlin.
To the
inside of
the shelter
End Rafter
