9
GROWSPAN
™
ROUND PREMIUM HIGH TUNNELS
Revision date: 10.25.21
FRAME ASSEMBLY
Gather the parts:
• All rafter assemblies
• Pipe 1.315'' x 75'' swaged (#131S075)
• Pipe 1.315'' x 73.5'' plain (#131P0735)
• 5/16" x 2-1/2" machine bolts (#FAG336B)
• 5/16" Nuts (#FALB02B)
• Lifts, ladders, and assistants
Frame Assembly Procedure
1. Using the proper lifts and with assistance, carefully
stand the first end rafter assembly and place the leg
pipes into the first set of ground posts.
2. Secure the leg pipes to the ground posts using the
5/16" x 2-1/2" machine bolts and nuts.
3. Place an interior rafter assembly into a second set of
ground posts. Secure the leg pipes to the ground posts
as previously described.
4. Position two (2) cross connectors near the top of the
interior rafter assembly as shown below.
5. Take two (2) swaged 75" purlin sections and insert
each through an upper clamp on the end rafter and
through the cross connectors near the top of the interior
(or second) rafter as shown above.
6. Verify that both rafters are plumb and properly spaced
(4' on center).
7. Tighten the upper cross connectors on the interior
rafter and tighten the end clamps near the top of the
end rafter to secure the first purlin pipes.
NOTE:
Do not allow the purlin to extend beyond the
end of the end rafter. See diagram below.
8. Continue adding rafters and purlin pipe until the frame
is assembled. Secure all purlin splices using Tek
screws. See Step 10.
NOTE:
Each purlin assembly consists of 1.315'' x 75''
(#131S075) swaged pipes (number is determined by
shelter length) and one (1) 1.315'' x 73.5'' (#131P0735)
plain pipe.
9. Finish each purlin run using the plain, shorter pipe
(#131P0735), and use the final end rafter to complete
the assembly.
NOTE:
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. 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.
CAUTION:
To prevent cover damage, the ends of the
purlins should extend no more than ½'' past the end
clamp. Position the bolt side of the end clamps toward
the “inside'' of the shelter (the same side as the purlin).
To the
inside of
the shelter
1/2''
10. Once all rafters are set and all purlins are in place and
secured, return to each pipe splice of each purlin run
and install a Tek screw through the pipes to secure the
joints if this was not completed during assembly.
Inside of
Shelter
Outside of
Shelter
Rafter
Ground
Post
IMPORTANT:
Brace
the first rafter in
position as needed to
keep it from moving.
Bracing is removed
after
additional
rafters are installed
and secured to the
other rafters.
4'
center-to-center
interior rafter
11. Return to each rafter and, using Tek screws, secure
the joint between the lower rafter legs (drilled pipe) and
the upper rafter pipes and continue with the following
procedure.
