Horizontal strapping under metal roofing


rikdekker
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I might be missing something but I can't see any option for horizontal strapping on roof for under metal roofing on and agricultural structure.

Anyone have any experience with this? Otherwise for Chief it would be a good checkbox option to include since it is such a common construction practice.

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2 hours ago, Kiwideziner said:

oops I think I misunderstood the question.

Me too. When I see the word "strapping" I think Simpson or coiled straps for wind bracing. Around hear we call them purlins - wood or metal, doesn't matter - same word used.

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3 minutes ago, Ridge_Runner said:

Me too. When I see the word "strapping" I think Simpson or coiled straps for wind bracing. Around hear we call them purlins - wood or metal, doesn't matter - same word used.

 

Must be a "Canadian" term.  Purlins was the word that was new for me.

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5 hours ago, Alaskan_Son said:

There are several methods, but if you use trusses, you can simply make them all Reduced Gable trusses and then manually drag an automatically generated lolookout right over the top of all of them.  

Interestingly enough  I just finished a job today that required 2x4 sleepers on an existing roof in order to support an over frame from an addition. Lookouts was my first thought but I couldn't control the pitch (the new roof was a 3in12 over an existing 9in12).

I couldn't believe how difficult it was to try to get a framing member to lay flat on a roof. I gave up, used a solid converted to a fixture so it would populate in the material list and model.

Same thing for bottom chord truss bracing on a vaulted ceiling. 

https://3d-viewer.chiefarchitect.com/go?share=265245076150206

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On 7/4/2020 at 8:46 PM, robdyck said:

Lookouts was my first thought but I couldn't control the pitch

 

Did you make a lookout , save it to your library , and then bring it back in ? , not sure if it works in your situation but it's how I do Purlins ( Roof Battens) when needed now.....

 

This is a thread from Last year with links to a video by Michael for his "Use of a Lookout" as a Purlin etc....

 

https://chieftalk.chiefarchitect.com/topic/20877-roof-profiles/?do=findComment&comment=172082

 

image.thumb.png.dcf15dda154e91d4b2c24a122654da96.png

 

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18 hours ago, Kbird1 said:

 

Did you make a lookout , save it to you library , and then bring it back in ? , not sure if it works in your situation but it's how I do Purlins ( Roof Battens) when needed now.....

 

Thanks for the tip Mick. Just for practice I gave it a shot. Here's what I did and the results:

  • I copied the existing roof plane
  • created a small room under it
  • changed it's lookout dimensions to 3.5x1.5 (flatwise)
  • changed the structure depth to 1.5"
  • replicated it in the z-axis in order to raise the framing layer above the ACTUAL sheathing layer.
  • built framing
  • deleted the temporary room
  • moved the framing only roof plane back into its original position
  • moved 1 lookout into the correct location on the x-axis only
  • framing result: it worked! the correct lookout is visible because of the correct grain direction. The incorrect lookouts are 'fixtures'
  • image.thumb.png.6786a0af0fc1a83c905e426c725fb0d4.png
  • The roof plane that represents the sleepers does cut the attic wall which I was able to correct with 2 clicks in the roof dbx
  • image.thumb.png.b9196d52e1fd8c3c4df4aacc61750f20.pngimage.thumb.png.309ad638b5a98d485d7efd33e5f2283d.png
  • I'm pleased with this because it's much more accurate as a model of the addition. The existing roof plane would remain in place, and the new roof plane will be on top of it. So this makes more sense than 'joining' the new roof to the old roof. Of course, they are joined...I'm just using 2 roof planes for the existing roof.

 

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Nicely done ....... you can save the Lookout to your Library as a CAD block , just remember to unblock it on inserting into a new plan so it becomes a 3D object and is seen in a 3D camera view. , it will then also automatically find the roof pitch.

 

TIP From thread below:     If this is happening to you......

any change to the roof , including doing a Plan Undo, will cause the Purlins to rotate out of position, once it happens Undo and Redo won't fix it, and I haven't figured how to stop that, but the "Fix" is relatively easy , in Plan View (2D) ,select one and using the Match Properties Tool > Rafter lookout ( name or Object Type ) you can easily select the whole lot and then simply open the DBX and click OK........closing it is enough to reset them to the Roof Slope.

 

Michael's "Fix" Tip for me back then...

what you’ve described is an issue that’s been around for a little while and is usually triggered by having auto framing for the roofs toggled off and Auto Rebuild roofs toggled on.  It stops happening if you toggle one or the other.  Super annoying though for sure.

 

There is more info in this thread and a Plan I posted back then :

https://chieftalk.chiefarchitect.com/topic/20877-roof-profiles/?do=findComment&comment=172148

 

 

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Wow, I had been offline for a while and when I log back in there is so much activity on this post.

Thanks all of you for your help.

Sorry for the use of local jargon. I just assumed everyone called it roof strapping but yes, absolutely, Purlin is the proper term.

My mistake and yes, Eric, searching with the proper terminology is very helpful.

I can use the suggested fixes but I guess the other half of my question was: why hasn't Chief included purlins as a standard option for building roofs so we don't have to take these time consuming roundabouts.

Don't get me wrong. I'm not complaining too hard because I think Chief is amazing and I have seen so many great improvements since I started with X2 before my hair turned grey. But on the drawing I was just working on I really didn't have time to p*ss around looking for cheats.

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8 minutes ago, rikdekker said:

why hasn't Chief included purlins as a standard option for building roofs so we don't have to take these time consuming roundabouts.

 

Because Chief as yet does not allow two Layers of Framing to be Auto Framed in a Roof Plane Structure......

 

Once you set it up once and have it in the Library it's not to bad if you really need to show it in 3D.

 

M.

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