50
Variable Terrain Installation –
Extruded
Calculate Rise/Foot Angle
To determine the hole enlargement size, first calculate the
slope rise/foot or the angle of the slope. Refer to the diagram
and examples.
• Measure section length in inches
• Determine section rise by using line level and measuring
vertical rise; measure rise in inches
• Divide rise by section length to get rise per inch
• Multiply by 12 to determine rise per foot
Ex: 24" rise ÷ 96" length = .25 rise per inch = 3" rise per foot
• Two methods exist for installing a fence on variable sloping
terrain — stepping and racking
• For either method, divide slope evenly into all sections
Stepping Method
With the stepping method, the rails remain horizontal and the
posts are extended to accommodate the variance in terrain.
Longer end posts should be used and holes for the opposite
side of the post can be field fabricated with template kit and
router or spiral saw to accept rails.
Racking Method — 10˚ or Less
With the racking method, the horizontal rails will follow the
sloping terrain.
When installing multiple sections, it is advisable to use an end
post and field fabricate the opposite side of the post to avoid a
jagged fence line.
Depending on the severity of rack (and specific fence style),
the following field fabrication steps may be necessary for
proper installation:
1. Enlarge holes in post to accept rails
2. Enlarge holes in rail to accept pickets
3. Shorten picket length
NOTE: Depending on severity of rack, post centers may need
to be decreased. Be sure to verify prior to
setting posts.
1. Enlarge holes in post to accept rails
- Determine angle or slope
- Place first post in hole and hold plumb
- Place rail next to post (not in routed hole)
at correct angle of grade
- Mark rail where post crosses it on angle
- Remove rail, measure the length of the drawn
angle. Add 1/8" to this length to determine proper
post hole size
- Enlarge post holes