Replies

1. 
   Stilletto | Jul 24, 2006 05:00am | #1

   I built a barn three years ago with trusses 8' OC with 2x4's on edge.  The 2x4's were nailed on with ring shank 60 d pole barn spikes.  

   Sheet metal roof over the top of the purlins.  No problems yet .   The plans were stamped by a local engineer.   I think you should be fine.

   What's wrong with me?  I could ask you the exact same thing.

2. 
   blue_eyed_devil | Jul 24, 2006 05:49am | #2

   The 60' span  and 4' centers would pose a challenge, especially if it is clearspanned. If it has a center bearing wall, it would be a piece of cake. The challenge would be setting them in a timely and efficient manner.

   I would mark the locations of all the lateral bracing while the trusses were on the ground in a nice neat pile. I would then designate the ones that were critical to the temporary setting process and mark them with a different colored paint. I'd then orfer up a large crane with a large spreader bar and devise a system for getting the trusses set and anchored without adding unnecessary temp braces.

   I would manage the 4' centers by dragging a 10' or 12' walk plank. The walk plank would be 2x10 or 2x12.

    

    

1. 
   DaveRicheson | Jul 24, 2006 01:29pm | #3

   I'd then orfer up a large crane with a large spreader bar and devise a system for getting the trusses set and anchored without adding unnecessary temp braces.

   Ya get a dog bone for that one!

   I've sent the crane operator searching for a long spreader bar more than once. Most will argue that they can lift a 60' truss with a standart choker, untill the first on folds up on them. Then it's "oops, I didn't think it would do that!".

   Scarey sh!d when your on the wall and on of those puppies folds and breaks over your head.

   Be hangin on by pucker factor.

    

   Dave

3. 
   BossHog | Jul 24, 2006 02:37pm | #4

   Setting the trusses with a crane and spreader bar is definitely a good idea. I've done too many repairs where trusses have folded up.

   Be generous with the erection bracing. Trusses this big can be hard to keep upright while they're being set and braced. They're very unstable until the roof is on.

   Make sure you use diagonal braces. Make sure your runs of bracing are fastened to something solid.

   Around here most guys use 2X4 purlins laid flat when the trusses are 4' O.C. Sure makes it easy to hit the board with the fasteners.

   One idea comes to mind that may or may not make it easier. If the trusses work at 4' O.C., they'll work 2 ply at 8' O.C. If your posts are 8' O.C. you can set botht russes on the posts and not have to put a header between them. Some guys like it one way, others like it the other way.

   That's gonna be one heck of a nice pole barn. Any chance we could get pics?

   Why is there a light in the fridge and not in the freezer?
1. 
   DaveRicheson | Jul 24, 2006 04:36pm | #5

   Around here most guys use 2X4 purlins laid flat when the trusses are 4' O.C. Sure makes it easy to hit the board with the fasteners.

   What centers do they use?

   I built my shop @ 4' o.c. and let the purlins in between the trusses at 2' o.c.. That kept my rafter tails to the plumb cut of the 2x4 top cord of the truss. I have a 2' soffit, so I didn't want a really fat looking gutter board.

   With 2x4 purlins flat, I think the extra 1 1/2" won't look to big on my current project, and it will sure reduce the labor of cutting and nailing them as I did on the shop.

   Do you know what kind of loading flat 2x4 purlins can be expected to carry?

    

   Dave

1. 
   BossHog | Jul 24, 2006 04:53pm | #6

   Most purlins I've seen are 2' O.C.The design of the purlins depends on the species of lumber and the loading. I have a chart around here somewhere, I think.Most guys around here just use SPF lumber and don't worry about it.
   From these honored dead we take increased devotion to that cause for which they here gave the last full measure of devotion - that we here highly resolve that these dead shall not have died in vain. [Lincoln]

4. 
   Brian | Jul 24, 2006 09:49pm | #7

   4/12 pitch or lower?

   Do you have a forklift?

   What size crew?

   Brace well!

   Planks inside the walls are nice for the guys nailing the tails.

    

    

   Treat every person you meet like you will know them the rest of your life - you just might!
1. 
   Blacky | Jul 25, 2006 12:26am | #8

   yes forklift...
   no spreader.. ya think a 24' pick would work as a spreader?
   I was thinking of nailing a temp 2x4 at about feet height to slide a plank on. I wouldnt be so stressed if they was 24" oc lot easier to walk on and truss locks and all them 60 footers are floppy theres so much difference above 48' on trusses.
   using them glue laminated fingerjoined poles nice and straight!
   I'm hoping to set a few tommorrow? if all goes well
   pics of course if I can figure out how to post
   thanks all
   Dan