- Rafter
Spacing,
Blocking Placement
for Proper Load Support of Polycarbonate
-
- - Blocking is framing
member that fits between rafters or studs.
-
- See Structural
Load page for further
explanation of snow and wind load.
- See Lexan Tech Data, pages 16-21, for load charts for bldg. dept.
- -
- See Poly
Position & Attach for mid-sheet attachment, roof & wall
sheets.
- 25mm
for 80-100 lb. load
-
|
Sheet
Thickness
|
Rafter
Spacing
|
35 lb.
load
|
45 lb.
load
|
60 lb.
load
|
|
6mm
|
24-1/8"
|
every 8
ft.
|
every 6
ft.
|
every 4
ft.
|
|
6mm
|
48-1/4"
|
every 2
ft.
|
every 1.5
ft.
|
do not
use
|
|
8mm
|
24-1/8"
|
not
needed
|
every 8
ft.
|
every 6
ft.
|
|
8mm
|
48-1/4"
|
every 2.5
ft.
|
every 2
ft.
|
do not
use
|
|
10mm
|
24-1/8"
|
not
needed
|
every 10
ft.
|
every 8
ft.
|
|
10mm
|
48-1/4"
|
every 3
ft.
|
every 2.5
ft.
|
every 2
ft.
|
|
16mm
|
24-1/8"
|
not
needed
|
not
needed
|
not
needed
|
|
16mm
|
48-1/4"
|
every 4
ft.
|
every 3
ft.
|
every 2.5
ft.
|
Specs for
selecting thickness, rafter spacing & blocking placement to
support load on roof or wall.
- Load
in lbs./sq. ft. Slope over 7/12 snow slides off. Spacing may
be less. No specs available.
-
- Bldg. dept. has snow &
wind load for your area. Supporting load is factor of frame
strength and poly. sheet rigidity. Follow chart and poly. will
support load.
-
- To allow for movement of
condensation past blocking, set blocking 3/8" back from outer
surface of frame, see Blocking.
When using 48-1/4"
on-center rafter spacing, a neoprene spacer is placed at
center of blocking. This eliminates bowing of sheet, see
Spacer
Install.
-
- Note: The sheet must be
supported on all 4 edges with a minimum of 1/2" of sheet bearing
on the frame. When using sheets that have been cut along the
width, and no longer have a rib at the edge, position so first rib
is supported by a minimum of 1/2" of frame.
- -
- -\-\-\-\Framing
Guide & Install
Manual Crucial read.-\