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mswalleye · Feb 11, 2011, 10:35 AM

I have this truss diagram and I can't find anyone that can tell me what the spacing it was constructed for. The outfit that sold us the truss can't tell us. I ordered for 6 foot o/c spacing but want to know where it says this on the truss. I see a small 6 to the left of the diagram. The writing below the diagram says "for spacing see above" so I have included three pictures of the left side of truss, right side of truss and writing above. If anyone knows for sure could you let me know. When I asked the outfit where I ordered them where it is marked she said "oh I just ordered for regular residential spacing" and when I told her that was not what we ordered she called me back saying it was for 6 foot spacing? Any help appreciated.

ma0641 · Feb 11, 2011, 01:57 PM

You have a 22'4" truss, 4/12 pitch. Were you planning on spacing the trusses 6 ft apart? There is no way to support or span for this type of truss, the load and deflection would be excessive. This looks like a standard residential truss, we use hundreds of them at Habitat for Humanity and space them 24"OC. What are you trying to accomplish?

mswalleye · Feb 11, 2011, 04:13 PM

Our intent was for a pole barn style car port. We had ordered 5 trusses to span 22'4" and they were to be spaced at 6 foot on center. The chords are 2 X 6 and the webs are 2 X 4. My husband figures if they were residential they would be 2 X 4 chords. I just want some kind of confirmation and you would think that the engineered diagram would give you this info?

ma0641 · Feb 11, 2011, 04:40 PM

2X6 would allow a greater load but my real question is-What are you going to use to cover the 6 ft. centered trusses. 6 ft. is an uncommon c to c distance. Building materials are primarily designed for 2 and 4 ft. That's why 4X8 plywood and drywall is so common. I see you are in Minnesota. You have a major exposure to snow load where you live and unless you had a very heavy roof system, snow would deflect the cover. You only have a minimal pitch 4/12 that is not particularly good at shedding snow. Why build a carport with heavy roof system? If you used a very light roof system, the roof could easily collapse. Every garage and carport I have built (Atlanta)has been 2X4 truss on 24" centers.

mswalleye · Feb 11, 2011, 05:31 PM

You run 2X4 on edge the length of the roof and then metal roofing on top. We ordered trusses for a 22'4" span, 6 foot o/c spacing, to handle our northern snow loads... it is not that uncommon really, my concern is did we get trusses to handle this spacing or did we not? And if they were engineered for this spacing, where does it say this on the diagram? Pole barn styles can be very solid and more economical so we went that route.

ma0641 · Feb 11, 2011, 06:56 PM

That explains thing better. Your purlins will support the roof structure. Metal roofs are light and will shed snow. The 2X6 will be much better than a 2X4. Ask them what "Deflection meets L/360.00 Live Load and L/360.00 Total Load" means. Sorry I can't help you better, we are much more used to standard truss design for residences and my thoughts were going that way.