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Scissor Truss Option Question

Scissor Truss Option Question

Scissor Truss Option Question

(OP)
I have an addition 26 feet in width and planned on using wood I-joists to construct the roof. The ridge beam would be 14 inches in depth and the i-joists are 11 7/8 inches in size. The height of the roof is 10 feet above the 8 foot walls to give the room a cathedral ceeling. The roof slope is 1:1.25. I could increase the roof elevation to 12 feet if necessary. I've even thought about raising the walls to 10 feet, although the existing house that it ties into has only 8 feet. The addition ties into the side of the roof and the existing roof has only a 20 foot height.
Another contractor suggested using scissor trusses since labor would be less expensive then the i-joists. What I wish to know is what would the interior elevation be using scissor trusses OR what would be the minimum inside slope for scissor truss (that a truss builder would be willing to make)?

RE: Scissor Truss Option Question

Why don't you try contacting a local truss supplier to give you an estimate on cost and an estimate on truss profile for that span?  

You would need to give them the required roof slope and truss span as well as required loads.

RE: Scissor Truss Option Question

Your outside pitch is 9.6/12.  A good rule of thumb for inside pitch is 0.5*outside pitch, or around a 5/12 in your case.  There are other variable that will affect this, however, this is usually a good starting point.  

RE: Scissor Truss Option Question

Watch for horizontal loads. Any truss mfg will give you a price. Just tell them the roof pitch, and that you want the highest ceiling possible.

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