sept1951 Posted June 18, 2015 Share Posted June 18, 2015 How do I create purlins for the roofing plan? It is required that purlins are located in the roofing plan if the joists are over 12'. And it has to be in the Roofing Layer. Please help me if you can? Thanks! Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 18, 2015 Share Posted June 18, 2015 I use lookouts edited to the size of the purlins that are lowered to just below the rafters. Just stretch them across the width of the roof plane. I use the transform replicate tool if I have multiple purlins. Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 18, 2015 Share Posted June 18, 2015 I just use the roof beam tool, it places them right up against the bottom of the rafters. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 18, 2015 Share Posted June 18, 2015 Hi Perry, I think it depends on whether you want it vertical, or perpendicular to the rafter. Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 18, 2015 Share Posted June 18, 2015 To me a purlin is a beam breaking the span of the rafters, so for me they are always vert. you can also change a roof beam to show any size you want. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 18, 2015 Share Posted June 18, 2015 Hi Perry, This is a purlin shown in the Oregon Residential Specialty code. They can be vertical as well; but then I would likely call it a roof beam. Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 18, 2015 Share Posted June 18, 2015 Thanks Bill, A vert. beam can also be a purlin around here. I very rarely do those anymore with all the structural stuff we do. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 18, 2015 Share Posted June 18, 2015 Hi Perry, Although this is still in the code book, we rarely see them in new construction here. We also see them in agricultural pole buildings. I looked up the definition, and it can be any horizontal member that breaks the rafter span. Link to comment Share on other sites More sharing options...
builtright3 Posted June 18, 2015 Share Posted June 18, 2015 Hi Perry, This is a purlin shown in the Oregon Residential Specialty code. They can be vertical as well; but then I would likely call it a roof beam. Bill, I do it the same as you have it here in your section. But I don't try to get it in the framing because we don't need to see the purlins in 3D so its just as easy to draw the purlins with bracing into the section. Link to comment Share on other sites More sharing options...
Kbird1 Posted June 18, 2015 Share Posted June 18, 2015 If the OP is from Downunder ? , Purlins (roof battens) are on top of the Rafters/trusses to fix the LongRun Metal Roofing too , so I think the OP may need to clarify. eg http://www.renovate.org.nz/1970s/roofs/roof-form-and-framing-original-details/ Link to comment Share on other sites More sharing options...
builtright3 Posted June 18, 2015 Share Posted June 18, 2015 I just use the roof beam tool, it places them right up against the bottom of the rafters. Perry, Once you put the beam in can you rotate it in the section to get what Bill is doing? Not that you need to do that but was curious if you ever tried it. You would the one that showed me how to edit in section views. Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 18, 2015 Share Posted June 18, 2015 Downunder, Now I see, they just like to cause trouble. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 18, 2015 Share Posted June 18, 2015 Hi Mick, We also call the horizontal members on top of the rafters, purlins in my region as well. These are used mostly in agricultural pole buildings. I use modified lookouts for these as well. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 18, 2015 Share Posted June 18, 2015 I guess it figures that they would put the purlin on the wrong side of the rafter downunder Link to comment Share on other sites More sharing options...
Kbird1 Posted June 19, 2015 Share Posted June 19, 2015 I am actually surprised there is no automated way to do this , I 'd think fairly easy to implement since as you say Bill a modified Lookout would do the job , fair bit of work to do them all manually every 900mm or so. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 19, 2015 Share Posted June 19, 2015 Mick, You can automate the process. Just stretch one lookout, then use the multiple copy tool. They will follow the roof plane. Then group select, and raise them as necessary. You'll have to raise the roof plane an equal amount. The only downside is you'll have to turn off auto roof framing. Link to comment Share on other sites More sharing options...
Richard_Morrison Posted June 19, 2015 Share Posted June 19, 2015 To me a purlin is a beam breaking the span of the rafters, so for me they are always vert. you can also change a roof beam to show any size you want. Yeah, but if vertical, you really should be cutting a birdsmouth into the rafter to avoid introducing lateral forces. Link to comment Share on other sites More sharing options...
Bill_Emery Posted June 19, 2015 Share Posted June 19, 2015 Hi Richard, If you're referring to the cross section that I posted; I simply showed where Chief shows a roof beam by default. I would have to raise it to create the birdsmouth; but I just posted it as a quick comparison of vertical, compared to perpendicular. That seemed to be the essence of the discussion between Perry and I. Link to comment Share on other sites More sharing options...
builtright3 Posted June 19, 2015 Share Posted June 19, 2015 It kind of funny when someone post a question and then you never hear from them again after several replies are going back and forth. Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 19, 2015 Share Posted June 19, 2015 Yeah, but if vertical, you really should be cutting a birdsmouth into the rafter to avoid introducing lateral forces. Not if you use an "A35" clip Link to comment Share on other sites More sharing options...
builtright3 Posted June 19, 2015 Share Posted June 19, 2015 Perry, As a Framer I have to ask this question: How do you put a diagonal brace under a vertical beam? Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 19, 2015 Share Posted June 19, 2015 I would just nail a 2x block under the purlin, that's the old way, now we just extend posts up inside the wall to a beam with an approved steel connection. most of the time an interior shear wall has to extend to the roof anyway. and for me at least purlins are 4x and bigger depending on the situation. Link to comment Share on other sites More sharing options...
Richard_Morrison Posted June 19, 2015 Share Posted June 19, 2015 Not if you use an "A35" clip Huh? Unless you use a birdsmouth, the rafter forces will be normal to the slope of the rafter. A clip doesn't change that. Link to comment Share on other sites More sharing options...
DRAWZILLA Posted June 19, 2015 Share Posted June 19, 2015 It works for my structural engineer. Link to comment Share on other sites More sharing options...
yusuf-333 Posted June 19, 2015 Share Posted June 19, 2015 This is common way we construct hones in our area, I use roofs as purlins, it takes no time. Link to comment Share on other sites More sharing options...
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