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E_MH_Mounting_instructions_Skylux_Climalux
Load graphs rafters
For roofs with plastic sheets or glass
The graphs below can be used to determine the free span for the rafter DX. This is the maximum length of the
rafter in function of the load and the depth (D) of your roof. The maximum bending is 1/200 (plastic sheets) or
1/300 (glass). Eg. A bending of 1 cm for a free span of 200 cm or 300 cm.
The load is related to the snow and
wind load.
Practical example:
The axis distance (AX) between the rafters is 1000 mm (= for plastic sheets with a width of 980 mm). The depth
(D) of the roof is 3500 mm. Determine the point on the graph “500 N/m² & 1/200”. The maximum rafter length is
4000 mm.
The maximum bending (1/200) with load is 20 mm. Less if unloaded.
The maximum deliverable length of the rafters is 5 metres.
2000
3000
3500
4000
5000
6000
600 700 800 900 1000 1100 1200
LD
AX
DX 1/200
350 N/m
500 N/m
750 N/m
1000 N/m
2000
3000
4000
5000
600
700
800
900 1000 1100 1200
LD
AX
DX 1/300
2000
3000
3500
4000
5000
6000
600 700 800 900 1000 1100 1200
LD
AX
DX 1/200
350 N/m
500 N/m
750 N/m
1000 N/m
