New opening in existing wall

[JStructsteel]

All,
any comemnts on this detail. Customer wants new opening, wants to install LVL first, then cut studs. 16'-0" opening. older house, floor joists nailed to side of studs, studs balloon framed to roof.

Thoughts?

 

[JAE]

It's an eccentrically loaded beam in your detail. There will be torsional twist in the new LVL beam.
The screws will have shear AND tension in some cases so not sure if I trust this detail.

I'd always try to sandwich the studs on both sides to keep the support concentric.

 

[Tomfh]

How are the existing joists current supported? Is there a ledger?

Like JAE, I don’t really like that eccentrically loaded screwed joint. How is that beam supported?

 

[XR250]

How are you getting the load out at the end of the LVL?

 

[JStructsteel]

Joist are nailed into sides of studs. Its a 1900's house.

At each end of the LVL is a perpendicular wall.

I get its eccentrically loaded, but not too much more than a beam with joists hanging off the side. I was counting on the floor diaphragm to help resist the torsion.

 

[XR250]

1) I would shim the rafter/band to the top of the beam to take some of the load off the connection. Maybe even add screws to the rafter band connection to spread out some of the connection load.
2) Install one ply of the LVL first with SDWS screws (not SDS) then install the other ply to the first ply. It is not a great way to attach things as there is very little leeway for missing the center of the stud.
3) I am OK on the eccentricity as the stud continuity ought to brace it.
4) Check bearing stress at the end of the LVL on the top plates.

 

[phamENG]

I might be tempted to use a light framing angle to connect the stud to the beam, and agree with XR that the design should accommodate putting up one ply at a time.

I don't buy the diaphragm taking torsion argument. There's no direct connection, for one.

 

[JStructsteel]

Here is an updated detail.

The joists are existing, so getting access could be hard to do a angle at each stud. What I could do is a couple screws into the ends of each existing joist too, they are flush with the edge of the studs that he LVL is on.

 

[bones206]

So no chance of shoring to allow installation of the new beam directly below the studs?

 

[XR250]

I have this request frequently from contractors.
For torsion, you could add some DTTZ1 or 2z on the joists.

 

[JStructsteel]

Bones, the client would prefer not to do that. I have not pushed the issue, was trying to get a good detail for side mounted.

XR250, I think I like that idea, perhaps at the 1/4 points? Do you think screws into the end of each joist would perform the same result?

 

[XR250]

I would rather use the hardware.
The DTT2Z's would probably be OK @ 48" O.C.
When I do these, the bottom of the LVL is usually flush with the bottom of the joists so I just uses straps to address the torsion.

 

[jerseyshore]

The downside of simple beams in balloon framed houses like this is that you'd have to double up the shoring on the floor above so I get trying to find a solution around that. Not everyone who is renovating a section of their 1st floor wants to worry about putting shoring up on the 2nd floor too.

 

[bones206]

Is there enough room for a face mount hanger to pick up each stud? Just as a boot and suspenders approach... the single line of fasteners on a narrow stud face makes me a little nervous about splitting.

 

[JStructsteel]

Bones206,
I could add that, they cant install until after the wall is opened up.

I will add notes about splitting, etc too, and if any issues to contact me.

Thanks

 

[JAE]

One other method would be to use a steel channel (channel web against the studs and channel flanges pointing outward away from the house.
With the channel, a pre-welded angle could be used to fit into a cut slot in the studs. Thus the load, coming down the studs, would enter the angle leg near the channel's shear center.
This is much more stable and a direct support.

Use a few lag screws through holes in the channel web to secure to the framing.

The challenge then would be supporting the channel at its ends.

 

[JoshPlumSE]

If this were me, I'd detail out a new header & king posts to support the opening. Then I'd point to the joists (on both sides) and say something like "Joists shoring during construction is the responsibility of the contractor".

That being said, I've done something similar to what JAE said before. Though that was for a reinforced masonry wall. No lag screws, obviously, we through bolted the channel header to the outside of the wall. For some reason, that detail feels a lot different than doing it for a stud wall.

Joist are nailed into sides of studs. Its a 1900's house.

If there were good hangers at the joists where I felt confident about how they would behave, I'd feel more comfortable with JAE's idea (channel support instead of an LVL). But, just toe nailing or such that is on the order of 100 years old? That worries me a bit.

 

[JStructsteel]

Right now the joists are supported to the studs via their current fasteners (side to side, its balloon framed). So adding a LVL does not change that connection, just that now the studs are supported to the LVL instead of bearing. The joist to stud connection has not changed.

am I missing something with the joist connection to the stud?

 

[XR250]

I think your solution is fine, JS.
You could add a 2x4 ledger between the studs face nailed to the LVL to help support the joists for some belt and suspenders.
Also, this is an old AF house. The wood is a lot more dense than the shitty SPF we use today. The fastener capacities will be higher.

 

[JStructsteel]

I will give the client a heads up to check the connections of the joists to the studs, and add fasteners if desired.
Thanks