Moving outer load bearing wall under a truss

[widstje]

I have a client that wants to bump a wall out 3 feet in the bathroom and wants the ceiling to be flat across the whole room. The problem is the (2)2x10 header above the current window and the rest of the load bearing wall is holding up a truss system. I can't put a beam back in to span the 12' where the old bearing wall would be because of ceiling height issues. Not sure how to transfer the load to the new wall or keep the load where it is. Maybe sister something to the bottom chord 3 feet or hang a beam above the truss somehow?

Anyone seen/done something like this before?

I'm a PE and this job is in Virginia.

 

[EngineeringEric]

You cannot sister the bottom chord! You can provide a flush beam which bottom chord is flush with the bottom of the trusses then provide top-flange hanging seats for the trusses. To be honest it can be done but if you are not comfortable with this work you should get a structural engineer who deals with this daily, I know a few firms in VA if you want some references.

Other problems for you once you size and detail the connections and figure how to do it (is it practical?)
-Provide columns
-Provide foundations
-Is lateral effected?
-Hows the new roof function?

 

[widstje]

Thanks Eric. I typically do simpler work so I'm beyond my comfort zone here. But I'd like to learn.

So your saying the end of the truss can be hung off a beam that's flush with the bottom chord as long as I can find a way to get load down to the foundation. Would you plumb cut the overhang to make room for the hanger? I've always stayed away for modifying the truss. It's a 30+ year old home so truss manufacture is unavailable to consult.

 

[msquared48]

In general, the truss needs to be supported at the same point and level it is now or stress reversals in the chord members could happen. If you could post a detail of the end connection at the support it would help.

Mike McCann, PE, SE (WA)

 

[EngineeringEric]

The minimum bearing area needs to be determined. a proper load path from top chord to bottom chord to seat needs to be determined. then the tails can be cut (do not cut the plate gussets). then install web-padded steel beam with 2x nailer on top flange. install hangers to pick up each truss.

during all operations trusses shall be supported (floor joists probably are not sufficient)

There is a good number of details and an expensive remodel. i would consult a different local PE in your area to run this by them. Buy an hour of their time or take them to a nice lunch (tell them before inviting to lunch why you want to meet)

 

[EngineeringEric]

You can learn this, but you shouldn't learn by only doing. you cannot afford a mistake if it leads to lawsuits or loss of life.

 

[woodman88]

I would cut off the overhangs and add a beam/hangers (be sure to check the post/foundation) at the end to keep the bearing location the same for the truss.

You could add members to one or both faces of the truss to extend it 3'. But the added span of the truss would require complete redesign and fixes for the increase forces in the truss. Not worth the effort or time IMHO.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.