9
GROWSPAN
™
GOTHIC PREMIUM HIGH TUNNELS
Revision date: 01.08.21 108179_80_81_82_83_84H
LAY OUT THE BUILDING SITE
After the site is prepared, lay out the building site.
Drive ground posts to the proper depth. The top of the post
will be one (1) foot above the finished grade when properly
driven.
Width of the frame is measured from the center of
one ground post to the center of the remaining ground post.
SQUARE THE SITE
Gather the parts:
• Ground posts
(Use top hole when attaching rafter.)
• 5/16" x 2-1/2" Machine bolts (FAG336B)
• 5/16" Nuts (FALB02B)
1. Identify a corner where a ground post will be positioned
and drive the first ground post into the ground.
NOTE:
Insert the ground post driver into the top of
the ground post to protect the post and drive the post
into the ground.
The top of the post will be one (1) foot
above the finished grade when properly driven.
Position the pre-drilled holes facing to the inside/
outside of the high tunnel so they can be aligned with
the bolt holes in the rafter legs.
4. String a line at least as long as the building from the
first stake at 90°.
NOTE:
A transit can be used to ensure an accurate 90°
angle, or the 3-4-5 rule can be used. Refer to diagram.
Using multiples of 3-4-5 such as 6-8-10 or 12-16-20
helps to maintain an accurate 90° angle.
5. After squaring the position of the building, measure
the length (center-to-center) and drive the next corner
ground post.
6. Repeat the same step for the last corner post.
NOTE:
The distance measured diagonally between
corner posts must be equal for the building to be
square.
7. Check all dimensions (and adjust if needed) before
driving the remaining posts to the required height.
8. After all corner posts are accurately installed, tie a
string line between the tops of the corner ground posts
on the same side of the frame. The string is used to
identify the tops of all remaining ground posts. The
string must remain tight and level.
9. Use a tape measure to mark the on-center locations
of the remaining ground posts.
See the Side Profile
diagrams in the Quick Start section for your frame.
10. Drive the remaining ground posts into the ground at the
required on-center rafter spacing and frame width and
the height identified by the string.
NOTE:
Verify that the holes in the ground posts are in
the proper position and that each post is plumb and
driven to the correct depth.
11. Continue with the
Rafter Assembly
steps that follow.
To align the bolt holes in the ground posts with those
in the rafter
after driving the ground posts,
insert a
tapered rod or pry bar into a ground post bolt hole and
turn the post using the rod or pry bar.
2. After the first corner ground post is in place, string a
line the width of the building (center-to-center) and
drive the second ground post into the ground just
enough to hold it in place.
3. Use a transit or another method to position the second
post, and to drive the post the same depth as the first
ground post.
Outside of
Frame
Inside of
Frame
Ground
Post
Attach rafter
using this
mounting
hole
