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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