Jack stud sizing for Long Header span

[The Frame]

I am building a house in Southern California where there is a sliding glass door on the first floor, with a second story above. The Header spans 13ft and is a Parałam PSL 3 1/2”x 11 7/8. All Lumber on this project is Select Structural Douglas Fir. My framer was supposed to use 3 2x4s as the Jack Studs, but chose to use a single 4x6 as the jack stud on each side. This is a 2x4 wall, so the 4x6 is sideways. Is this an acceptable way of framing out a header? I have never seen it done this way, are there any drawbacks to this design?

 

[jayrod12]

You have more bearing than specified. You're fine. A solid 4x6 is far better than a built up 2x4 in most cases.

 

[SWComposites]

… assuming the framer accounted for the 4x6 being 1 inch wider than 3 2x4s. …

 

[The Frame]

@Jayrod12 I get that it has more bearing, and the framer did account for the extra 1”. the reason I was concerned was because I thought that trimmers are built up because of the cross grain strength it provides. I thought 2x is more stable and as the 4x dries out it is more prone to warping and twisting. I have just never seen it done that way. I could be wrong, and that’s why I am asking here to see what other people thought about it

 

[jhnblgr]

Typically the bearing for the header is the determining factor, it is not always the case but a quick calculation could be used to verify if it is adequate. The jack stud axial capacity should be checked. Is there a wind load component?

 

[XR250]

Yes, potentially, the 4x6 will warp and twist.

 

[The Frame]

Would it be better at this point to replace the 4x6 with a 3 1/2”x5 1/4” parałam column for stability. The 4x6 is quarter sawn free of heart center, with no knots