Tie-Beam to Wood Beam

[kmart30]

I have a 1 story home with conventionally framed roof sitting on a old brick wall with a tie-beam on top running around the perimeter of the home. They want to put a 10' opening in the wall to a new addition. I have no idea what is in this tie beam as far as reinforcing to see if it can span the new opening. To make it easier to construct I was thinking about designing a wood beam to span this instead of going back with a reinforced beam or lintel. Im concerned about the shear line loads adequately transferring in and out of the different materials and what a good connection would look like. Should this even be a concern as long as the shear gets transferred? or should I just spec out a concrete beam/lintel, dowel in, and call it a day?

 

[Shotzie]

Could you leave the tie beam intact and slot in a steel angle below it designed for gravity loads?

 

[kmart30]

Wont fly without a hefty section assuming Im not getting any capacity from the tie-beam. I think they already made the opening in the wall and haven't reported any cracking but besides the size of it I dont know anything else. So to be conservative I would have to design whatever I choose to resist the load of the roof and DL of the tie beam...right?

 

[Guastavino]

@kmart30...people will try most anything when it’s your liability on the line...do what you feel comfortable with. I would say through in a precast concrete lintel and be done with it if they want the look to be the same. If that won’t work, maybe a C8 channel bolted to the tie beam at 16” o/c extending past the opening each side that is sized appropriately.

And respectfully, what size wood beam were you thinking if a steel angle wouldn’t work?

 

[KootK]

What's the nature of the shear loads you're dealing with here? Is this wall itself a shear wall and you're concerned about the tie beam distributing load between wall segments? Or connection of diaphragm shears to the wall?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[kmart30]

What I meant was that the contractor prefers using lighter materials he can easily get at a home depot or similar. Much easier to put up a 2-ply or 3 ply beam with kings and jacks then a heavy steel angle or precast lintel and supports. You are right about it being my liability but I dont mind working with the contractor if its the same work for me and helps him out. I think its good business but yes if anything else CYA.

This was an exterior shear wall that will now become an interior shear wall with the added addition. Yes, I was talking about the shear that would be getting transferred into the wall segments.If we removed the tie beam in the opening and added a wood beam, would just adding a simple strap from wood beam to existing tie-beam be suffice to transfer the shear into the next wall segment?