Mixing 2x Framing to meet 11 7/8 I-Beams ?

[scuba_dave]

I should have ordered 1 more I-beam maybe....
I'm planning on building a 5' long wall that will border the staircase to the walk up attic. I'll need to span 4' to the 2 outer walls
On the left the 1st red line is a span that will be in the floor, ceiling will be uninterrupted
The 2nd red line in the same area will be over the attic door, the door will be on the 1st step - opening towards you & against the wall
I had planned on using a 2x 2x12 as a header across the door opening. Then a cripple wall above the header to match I-beam height
Between the step, door RO, header & cripple wall it will equal the I-beam

The long red line that parallels the attic stairs & then goes over the sunroom stairs (40" wide), Total length is 10', but it will cross a supporting wall that is for the top of the stairs, Even tho its not thet great a distance I am thinking of using an LVL to match the I-beam height

So I would need a 4' & 10' 11 7/8" LVL
I think nailing reg lumber into an LVL is easier then an I-beam
I think that's why I did not order another I-beam
Does anyone ever use 2x10 & then a 2x3 (or plywood?) as a top plate to equal the I-beams? Or cut down a 2x4 to match height?

The long wall that runs on the opposite side of the stairs is the existing house. I'll be nailing/screwing the stair riser into that wall. I'll have 3 risers for added support

I'm again probably over thinking all this
But my last house was built in 1905 & sagging all over

http://i4.photobucket.com/albums/y105/Daveywb/Construction/AtticStairs.jpg

[pushkins]

Your always going to be safe with an LVL over std. 2x lumber. A 11 7/8 LVL will hold much more than a 2x12" hands down.
You can safely use cut down 2x4's to pick up the other 1 7/8" or as you mention some ply, it's only a filler the 2x material is the load bearer.

If it were me, I'd be ordering one more LVL @16' and cutting out my two pieces (4' & 10')

[scuba_dave]

Yeah that's what I figure I will do
I bought the next grade I-Beams for a stiffer floor, better LVLs' for the garage support. No sense cheaping out now over less then $100
And I think getting to the 11 7/8" with 2x could be a pain

Thanks again

[scuba_dave]

I picked up the LVL & installed it
Then across 2 of the load bearing runs I doubled it up with a 2x12
The 9' 9" run will be cut almost in 1/2 by a support beam I will install that will border the stairs going down to the sunroom. So a lot more support then I needed, but the support & 1/2 wall were an after thought - the measurements work so I figured why not. I don't think I can have too much support for the stairs

Thanks, its starting to come together