Unsupported roof span


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Old 07-11-14, 11:53 AM
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Unsupported roof span

Hey all,

First time building a roof and I was wondering if I my idea will work... I have uploaded a picture for reference. So i have 6x6 posts which will be supporting doubled up 2x12's for a roof. I have a unsupported corner as that will be the entrance to the gazebo. I was wondering if i can still do a standard square frame for the roof, with the south east corner being unsupported or if i have to make the frame go from the bottom-middle post to the right-middle post and have an unconventional roof shape... any ideas/suggestions?
 
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Old 07-11-14, 05:01 PM
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Do you really need 12 ft of wrap around stairs, for the entrance? I imagine it can be done but I don't have the ability to draw those plans.
 
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Old 07-11-14, 06:57 PM
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There is no 12 feet of wrap around stairs... all of that space is open to a lower level of the deck... there is a 7" inch step... and yes i do want it to be open, just cant live with a post splitting up the space...
 
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Old 07-13-14, 01:47 PM
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Anyone?? Anyone?? Anyone??
 
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Old 07-13-14, 03:23 PM
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Basically, you are wanting blessings on a 6' cantilever. At the corner, will there be a 2x12 beam connecting across the cut off part? How much load will there be above the opened corner? You say gazebo, so I hope only roof load.
 
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Old 07-14-14, 04:58 AM
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I'm just not sure if it can be done... just wanted ted to ask people who have built roofs before. What do you mean will there be a 2x12 beam connecting the cut off part?
My plan was to use (2) 2x12 as the rim of the roof and if necessary some lateral support (in the form 4x4 at 45 degree angle) from the post to the unsupported 2x12 section... but if its totally sound without it, that would be ideal....
The only load is roof load.
 

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Old 07-14-14, 05:21 AM
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@ Dblocks "The only load is roof load."

I'm in central Maine and we have something like a 40" snow load, which we can receive in a single storm. Add in some rain and ice and before people can get outside to rake off as much as possible many structures fail. The design load for your location is much more than the roof itself and anything you build should have an engineers stamp of approval.

My guess is that the distances you are talking about are well within engineering range, but you should have them specify the design and materials.

Bud
 
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Old 07-14-14, 05:52 AM
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Originally Posted by Bud9051
@ Dblocks "The only load is roof load."

I'm in central Maine and we have something like a 40" snow load, which we can receive in a single storm. Add in some rain and ice and before people can get outside to rake off as much as possible many structures fail. The design load for your location is much more than the roof itself and anything you build should have an engineers stamp of approval.

My guess is that the distances you are talking about are well within engineering range, but you should have them specify the design and materials.

Bud
I thought the term "roof load" included things like snow/wind... guess I was wrong, sorry.
 
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Old 07-14-14, 06:25 AM
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You may be correct. I was just interpreting your reference to roof load as just the "roof", probably my bad. But in any case I suspect your location is substantial.

I use a local lumber yard for all of my materials and find them very helpful for basic engineering. Their software is capable of providing engineered trusses so they are very familiar with local load conditions. They also can provide some engineered materials that would be better than 2x12's for that cantilever. I'm in the process of jacking up some floors on my 35 year old house and it is a reminder as what old building practices had to deal with.

With your 12' wall supported half way, there will be as much uplift on the other end as the downward force you are wanting to support. Essentially, that center supporting 6"x6" may be holding double the load.

Then you have wind conditions. You are not in Florida, but a 70 mph wind can cause a tremendous amount of lift, thus everything needs to be secured for some reasonable design parameter.

I've build a lot of sheds and I'm always guilty of over-building, but none of them have ever failed to satisfy.

Enjoy
Bud
 
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Old 07-14-14, 01:38 PM
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My question regarding the load, was to really find out if there was to be any other flooring or such above. I guess with a gazebo, there would not be, by design. Also, I was asking if there were to be a beam across the void where there is no post, or if you were going to rely on square framing for the protrusion.

Something like this:

Name:  roof.jpg
Views: 1005
Size:  12.0 KB
 
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Old 07-14-14, 06:00 PM
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Chandler,

I was thinking of doing the exact thing you showed in your picture... but im not sure if it will be able to support the roof load...i dont think the 6x6 posts will be able to support (2) 2x12 from both the square framing and lateral beam... would you recommend the square framing being doubled up (for that section) or the lateral beam?
Ill have to do some math, i might be able to fit them both being 2x...
 
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Old 07-14-14, 06:15 PM
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How do you plan on attaching your doubled framing to the 6x6's? Are you using any Simpson Strongtie brackets?
 
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Old 07-15-14, 01:45 PM
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I pre-notched the top of the 6x6 post so that i can bolt the 2x12 directly to the post... for the ones supporting the lateral beam i would have to use a simpson bracket i suppose.
 
 

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