|
Size (mm) |
Light Sheet Roof N2 – Rafter Spacing (mm) |
|||||
|
Single Span Rafters |
Continuous Span Rafters |
|||||
|
300 |
600 |
900 |
300 |
600 |
900 |
|
|
140×42 |
6.4 |
5.9 |
5.3 |
8.0 |
7.4 |
6.3 |
|
190×42 |
7.7 |
7.1 |
6.7 |
9.6 |
9.0 |
8.5 |
|
240×42 |
8.8 |
8.2 |
7.8 |
11.0 |
10.4 |
9.9 |
|
290×42 |
9.8 |
9.2 |
8.8 |
12.3 |
11.6 |
11.1 |
|
140×65 |
6.6 |
6.2 |
5.9 |
8.4 |
7.8 |
7.4 |
|
190×65 |
7.9 |
7.5 |
7.2 |
10.0 |
9.4 |
9.0 |
|
240×65 |
9.0 |
8.6 |
8.3 |
11.3 |
10.8 |
10.4 |
|
290×65 |
10.0 |
9.6 |
9.3 |
12.6 |
12.1 |
11.7 |
|
240×80 |
9.1 |
8.7 |
8.4 |
11.5 |
11.0 |
10.6 |
|
Size (mm) |
Light Sheet Roof C2 – Rafter Spacing (mm) |
|||||
|
Single Span Rafters |
Continuous Span Rafters |
|||||
|
300 |
600 |
900 |
300 |
600 |
900 |
|
|
140×42 |
5.8 |
4.0 |
3.3 |
5.8 |
4.0 |
3.3 |
|
190×42 |
7.7 |
5.5 |
4.5 |
7.9 |
5.5 |
4.5 |
|
240×42 |
8.8 |
6.8 |
5.5 |
9.8 |
6.8 |
5.5 |
|
290×42 |
9.8 |
8.1 |
6.5 |
11.6 |
8.1 |
6.5 |
|
140×65 |
6.6 |
5.0 |
4.1 |
7.3 |
5.0 |
4.1 |
|
190×65 |
7.9 |
6.9 |
5.6 |
10.0 |
6.9 |
5.6 |
|
240×65 |
9.0 |
8.6 |
7.1 |
11.3 |
8.8 |
7.1 |
|
290×65 |
10.0 |
9.6 |
8.6 |
12.6 |
10.7 |
8.6 |
|
240×80 |
9.1 |
8.7 |
7.9 |
11.5 |
9.8 |
7.9 |
Span values are in metres
Loading Data:
Dead Load of roof: Light Sheet Roof with no ceiling, maximum 20 kg/m2
(Covers standard light sheet roofing materials, for roof pitch maximum 35deg)
Wind Load taken as N2/C2 in accordance with AS 4055 Wind Loads for Housing
ETH LAM GL beams are manufactured straight, without any camber built into the beams.
Notes:
- Minimum bearing lengths for support of rafters: 35mm on end supports, and 45mm internal supports.
- The span value shown is the distance between centrelines of supports.
- For continuous spans, the adjacent rafter spans may be different, but look up the larger of the spans, and the shorter span must be more than 50% of the larger span. If this rule is not met, then consider the rafters are simply supported, and look up the larger span in the single span table.
- Deflection criteria: for dead load, the lesser of Span/300, or 20mm, and for Roof Live Loads, Span/250.
- Where there are conflicts in design between loading codes (AS/NZS1170 series), timber code (AS1720.1-2010) and AS1684.1-1999, the loading codes and timber codes take preference.
The above span table values have been designed in accordance with the following codes:
- AS1720.1-2010 Timber Design Code
- AS1170.0, .1, .2-2002 Loading Codes for Limit State design, Live Loads, and Wind Loads respectively.
- AS1684.1-1999 Design Criteria for Residential Timber Framing.
Download Span Table as acrobat pdf.
Click below to find out more or contact us on: John Carroll 0414301515 and Colin Carroll 0421273887
Email for a price or more information: John@carrollswholesale.com, Colin@carrollswholesale.com
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