Residential roof truss interior walls being removed. 1

[shacked]

I have a client that wants to remove some interior wood stud walls in a single story house. The roof system is 2x4 roof trusses and span approximately 30ft. Let me also say that I have very limited experience with roof trusses and probably no knowledge of typical rules of thumb concerning design of residential roof trusses.( I specialize in custom residence and hillside homes)

I have attached the roof plan with dashed red walls to be removed.

I went into the attic at the wall line at the red cloud to the right, behind the master bedroom and I verified that there is gap between the bottom truss chord and the dbl 2x top plate. Based on this I am assuming that that wall line in non bearing.

This is located in Southern California so there is no snow load so I do not believe that truss arching would be an issue here.

My question is, in lieu of running a calculation for the truss would a field observation such as this be an acceptable way of determining if the roof trusses are bearing on an interior wall?

Thanks

 

[dauwerda]

If they are factory built, metal plate connected trusses I would expect that they are designed to clear span and that none of the interior walls are load bearing.

 

[jayrod12]

I agree with dauwerda. 30 feet is nothing for metal plate connected trusses. And since you did the proper homework and went and confirmed the presence of a gap, you're already a step ahead. With the gap there, that would confirm to me they're non-loadbearing. It's odd that there's a gap, because honestly in single family residences where I practice, almost no one puts in the appropriate gaps.

 

[Canuck65]

I agree with the comments above, but will add another observation. If the location of the wall does not line up with a panel point in the bottom chord of the truss, it is almost certainly not a load bearing wall. A load bearing wall typically would not provide support to the bottom chord of a pre-engineered wood truss between panel points.

 

[shacked]

Thanks guys, that is exactly what I had assumed, all of the above.

 

[Ron247]

I agree with all the comments above. I would just add "provided they are not scissor trusses". The panel point location is one of the best indicators it is not load bearing even on a scissor truss.

 

[msquared48]

I agree too.

Mike McCann, PE, SE (WA, HI)

 

[dik]

even if clear span and not interior bearing walls, just be cautioned that you can have some minor cracking due to the change in the loading regime.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik