DESIGN OF PURLINS

[thomasian]

i am currently designing timber purlins, some references use the inclined spacing for roof(from KPa to KN/m ) some references use the horizontal spacing, which do you think should i prefer. although it would make a slight difference, i would like to make a correct analysis and design.

 

[Ginger]

Ian<br>
<br>
Whether you use the horizontal (ie plan) spacing of purlins or the inclined purlin spacing depends on whether your load on the roof has been applied on plan or parallel to the rafter (ie inclined). I would match plan load with plan purlin spacing to be consistent and vice-versa for inclined. As you correctly state, the difference in result is minimal. As for the terms KPa & KN/m , 1 Pascal = 1 Newton per square metre, so to convert the figures you multiply the KPa by the purlin spacing (in metres) to get the conversion into KM/m.<br>
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Regards<br>
<br>
Ginger